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What would you do?

Printed From: CorrectCraftFan.com
Category: Repairs and Maintenance
Forum Name: Engine Repair
Forum Discription: Engine problems and solutions
URL: http://www.CorrectCraftFan.com/forum/forum_posts.asp?TID=47436
Printed Date: April-16-2024 at 1:37pm


Topic: What would you do?
Posted By: poecs13
Subject: What would you do?
Date Posted: May-11-2019 at 3:26pm
I purchased my first Nautique, a 2005 Ski 206, two years ago. In other posts you will see that in the time I've owned it we've been taking care of engine issues since we got it. Appears that the boat has not been in the best care over the course of it's life. At any rate, we got all of the engine issues ironed out and were really excited to replace the vinyl, stereo etc this year and finally have a boat that we could just maintain. Or so we thought...

I have had it out multiple times and have skied several times already this year with no issues. I took it into the dealer to have them give the boat a once over before the heavy summer season. They called me to tell me that the engine had a knock that they suspected to be a bent rod and that the whole engine would either need to be rebuilt or replaced altogether.

Lots of things on my mind...did I miss the knock through the first few months of the year? Is it plausible that it just magically occurred under their care?

I am thinking of taking it for a second opinion to confirm their diagnosis, but if it turns out to be true, my wife wants to get rid of this boat and trade for a newer single-owner boat where we have a more precise idea of the boat's history and how well it's been cared for. (She actually said the words that every man dreams of: "Honey, I think we need to get a new boat.")

The way I see it we have a few options:

A) Rebuild/Replace the engine and keep the boat, knowing that after replacing the entire engine we're not likely to run into many more unexpected issues due to lack of care/maintenance of the engine by previous owners.

B) Sell the boat "as is" and let someone else deal with deciding on how they want to repair it.

C) Repair and sell. And if this option, will rebuilding or replacing the engine get better resale value?

Is there anything else that I'm missing/not thinking of? I have a basic working knowledge of engines but I know there is far greater expertise among the members of this site. Any insight is greatly appreciated!

Charlie



Replies:
Posted By: 8122pbrainard
Date Posted: May-11-2019 at 4:46pm
Originally posted by poecs13 poecs13 wrote:


I am thinking of taking it for a second opinion to confirm their diagnosis,
Charlie

Charlie,
I feel this is in order. If you do, report back.

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/diaries/details.asp?ID=1622" rel="nofollow -

54 Atom

/diaries/details.asp?ID=2179" rel="nofollow - 77 Tique

64 X55 Dunphy

Keep it original, Pete
<


Posted By: KENO
Date Posted: May-11-2019 at 8:20pm
Charlie

Me and that guy Pete in the other reply to your post usually find ways to disagree on things but not in this case.

From a previous post, it seems that you had it at Buxton Marine before and that's maybe where it is again

To start with, I'd be going there and having them run it for me to be able to hear the knock that you didn't hear in your time using it. I'd want to hear it in the water under normal conditions, not on a hose in their lot or repair bay.

Then like Pete said, get a second opinion about the noise if there is one that's new to you and where it's coming from.

Damper plates, transmissions etc can be a source of some funny noises.



Posted By: MrMcD
Date Posted: May-12-2019 at 5:48am
You have good advice already. Listen yourself and if there is a strange noise, get the second opinion.
A 2005 would have one of the GM LS style engines I think?
Those are super durable and run a much improved oiling system. A failure would be pretty odd.
Granted, maybe someone ran it out of oil at some point and caused damage but you said you were sking already and it ran great?
If there is no noise or if a new noise showed up while in the shop it might be worth investigating or bringing in the better business bureau.

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Posted By: GottaSki
Date Posted: May-12-2019 at 9:02am
Yes, second opinion is in order

They can make some clunking first revolutions of the season and still be good to run, maybe the heard that and need the work?

That vintage should have the lt1 based engine I suspect

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"There is nothing, absolutely nothing, half so much worthwhile as messing around with boats...simply messing."

River Rat to Mole


Posted By: poecs13
Date Posted: May-12-2019 at 10:40am
Thank you for the replies so far.

Yes, the engine is the PCM 6L ZR6 based on the GM LS series. When I purchased the boat in June 2017 it had 415 hours and it is now up to 485. Way too young to be requiring a rebuild if it was cared for properly all it's life, right?

As I keep thinking about this, another thought has crossed my mind. Last year I posted about a " %20http://correctcraftfan.com/forum/forum_posts.asp?TID=43319&KW=&PID=555490&title=strange-flooding-condition#555490" rel="nofollow - strange flooding condition ". One of the things that the tech told me over the phone last week is that the cause of the bent rod was likely hydrolock, either water or too much gas in one of the cylinders. Last year, when they weren't able to resolve the flooding issue, my service advisor said that the extra flooding wouldn't do any harm to the engine, I would just have to go through the inconvenience of clearing it with the throttle wide open while starting. He said that they would take another look at it in the spring when I brought it in for annual maintenance. I will admit to my negligence here because I probably should have taken it to another shop at that time or followed some of the suggestions provided by CCF members in that post. Because my service advisor didn't make it seem like a major or urgent issue I decided to do what he advised and live with it until this year. Now I'm wondering if the failure to resolve that issue did cause extra fuel in the cylinders and therefore the bent rod?

I have the day off tomorrow so hopefully will be able to spend some time fully understanding what Buxton believes the issue is and pulling it on to a second opinion. I will keep you all posted!


Posted By: tryathlete
Date Posted: May-12-2019 at 12:26pm
I’m wondering if a bent rod would present itself by showing lower cylinder pressure on a compression test or even better yet with a bore-o-scope examination (piston not reaching TDC due to loss of rod length caused by hydro lock). Is there any way short of pulling the engine and then the oil pan to examine for hydro lock?

Using some form of localized listening device that I’m not familiar with might pay dividends too. Hope it’s a damper plate or something a bit less costly to alleviate!


Posted By: tryathlete
Date Posted: May-12-2019 at 12:29pm

This kind of bothers me;

“They called me to tell me that the engine had a knock that they suspected to be a bent rod and that the whole engine would either need to be rebuilt or replaced altogether”

If it’s a bent rod and just one cylinder, why not pull that bad rod and replace it? Even replacing all of them, pistons too— not prohibitively expensive..... as long as you get to the root of the hydro lock (if this is really the root).


Posted By: gun-driver
Date Posted: May-12-2019 at 3:16pm
Link? Guessing this is the one
http://www.correctcraftfan.com/forum/forum_posts.asp?TID=43319&title=strange-flooding-condition" rel="nofollow - http://www.correctcraftfan.com/forum/forum_posts.asp?TID=43319&title=strange-flooding-condition

1) What was causing the flooding?
2) There was no mention of it not turning over (cranking) if it hydro locked would it still be able to crank/turn over with the starter.


Posted By: MrMcD
Date Posted: May-12-2019 at 4:35pm
Flooding, probably a leaking injector can cause hydro lock. That can bend a connecting rod.
If that is the case the head on that side would need to be removed, the oil pan and that one rod could be pulled and replaced.
Have the piston measured, it may have zero damage.
I have seen this issue before and you can see where the piston is tapping on the cyl head.
Most times the bend in the rod is minor and hard to find but you will see the shiny spot where the piston taps the head and that spot may be small so pay attention on tear down.
To pull the pan off the engine will need to be out of the boat most likely.
GM recommends putting the new piston with new rings in WITHOUT honing the cylinder.
Modern rings like a very smooth cylinder and yours should be perfect for the new rings as is.   If your Fuel leak washed the cylinder wall and caused scuffing on the cylinder wall you will need to hone that cylinder and maybe it would have to be bored to a larger oversize piston. I hope that is not the case.
That 6.0 L LS engine is a beast and very durable. 550 hours is nothing if it is taken care of.

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Posted By: MrMcD
Date Posted: May-12-2019 at 4:46pm
I just went back and read the previous post Gun Driver copied.
You had a bad injector and used the boat for many hours in that condition.
Since power soft the injector was either plugged and not giving you enough fuel or stuck open allowing to much fuel in that cylinder, maybe not closing and leaking while parked.
It may have some cylinder damage but the fact it ran great after the repair points to it being in pretty good shape.
You might check compression in they cylinder before tearing anything apart.
It needs to be within 10% of your other cylinders.



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Posted By: GHTILL
Date Posted: May-12-2019 at 11:47pm
Curious as to where you first purchased this boat? Was it through Buxton? I have recently had some service work done there and wasn't very impressed. I have delt with these guys for years and have never had any problems up until now. Don't want to bad mouth anyone but......

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TWSS


Posted By: GHTILL
Date Posted: May-13-2019 at 12:36pm
Sorry after further research I noted that you had not originally purchased the boat from Buxton. We have a total of 5 boats from them. Most of them used,but maintained by them.
I just think their service dept is getting a little too overwhelmed by the volume they are doing right now.

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TWSS


Posted By: tryathlete
Date Posted: May-13-2019 at 1:14pm
Originally posted by GHTILL GHTILL wrote:

Sorry after further research I noted that you had not originally purchased the boat from Buxton. We have a total of 5 boats from them. Most of them used,but maintained by them.
I just think their service dept is getting a little too overwhelmed by the volume they are doing right now.


It’s got to be tough to hire qualified marine mechanics in this economy! How do you keep them in November-March?


Posted By: poecs13
Date Posted: May-13-2019 at 8:35pm
Went to Buxton this morning, the knock is indeed there and it most definitely was not there when I dropped it off. I definitely would have noticed it. The tech explained to me that after he swapped out the oil, filter, impeller and trans fluid, he went to fire the engine for the first time and it hydrolocked instantly. When he opened up the cylinder, gas was found. After he cleared it and restarted the knock was there, and bent rod is still the suspect. I did take it for a second opinion from an independent mechanic and he agreed that a bent rod is likely the issue and rebuild would be required.

Is it possible that my flooding issue from last year was the root cause of the excess fuel? I believe the tech I work with at Buxton is fantastic but the service advisor is the one who led me to believe that the flooding wouldn't do any permanent damage to the engine. Am I way off base here in thinking that the two issues are related?

I will also note that I have been amazed at how poor the level of customer service has been at Buxton. I have had to initiate every single contact, and they have made no apology or attempt to resolve the fact that the rod bent under their care. Their one saving grace with my experience has been the tech who spent the longest amount of time with me explaining everything. I have a feeling that selling G-series boats with six-digit price tags is a lot more important to the company than servicing 15 year old ski boats.

So where to from here? My wife is strongly in the camp of selling as-is and getting a new boat altogether. Any other ideas/options I should pursue?


Posted By: JoeinNY
Date Posted: May-13-2019 at 9:35pm
So yeah the entire fuel system likely needs to be cleaned out - and the injectors replaced along with pulling the engine and dropping in a new rod/piston.   Any chance Buxton has something on the lot you want to buy? Maybe they are willing to work with you and not discount your boat as a trade so much/make a bit less on the sale to keep you from taking too big a hit.   Keeping a boating wife a happy wife has some value.   



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http://www.correctcraftfan.com/diaries/details.asp?ID=1477 - 1983 Ski Nautique 2001
1967 Mustang 302 "Decoy"
http://www.youtube.com/watch?v=cO5MkcBXBBs - Holeshot Video


Posted By: poecs13
Date Posted: May-13-2019 at 9:41pm
That thought had crossed my mind. Unfortunately, the only ski boats they have are closed bow which is a dealbreaker for us.


Posted By: MrMcD
Date Posted: May-15-2019 at 1:17pm
If it is a good boat fix the engine and move on.
As mentioned those are great engines and run a long time.
You could have the one rod changed and be back in business.
You don't need a Marine shop to do this.   Every GM and GMC Truck, Suburban and Tahoe run the same type engine. Any good shop can fix the Rod for you.
Since it is hydrolock damage the rest of the engine should be just fine.
The piston in the bad cylinder may be fine also. A machine shop can measure it and tell you.
Why it got damaged? Good Question.   The shop may have had bad luck and just because they were the next one to turn the key they bent the rod.
The injectors are pretty bullet proof normally unless PCM changed away from the OEM injector in these engines.
A boat engine pops out with little drama compared to the same engine in a car so it should not take that many shop hours to repair this engine. My 2 cents.

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Posted By: poecs13
Date Posted: May-15-2019 at 7:33pm
What exactly is involved in removing the engine, getting it ready to be re-built by a machine shop and then reinstalling? Buxton said it would be about $6000 to get all of that done. I just spoke to a shop that will do the rebuild for $2000, but I would have to bring them a pulled engine. I am quite handy but have never tackled any sort of major engine work before. What would I need to be able to do in order to remove and reinstall the engine? And how much time involved?


Posted By: 8122pbrainard
Date Posted: May-15-2019 at 9:35pm
Originally posted by poecs13 poecs13 wrote:

. What would I need to be able to do in order to remove and reinstall the engine? And how much time involved?

Charles,
It sounds like you are pretty mechanically inclined so pulling the engine yourself may not be a bad idea. The biggest issue for you would have a means of hoisting the engine out of the boat. Some have rented engine hoists or built gantries or even used a big tree to attach a hoist to!! Beyond that, it's a matter of disconnecting electrics and mechanicals. Once you get the engine back, the order is reversed and then you'll need to do an engine alignment to the prop shaft.

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/diaries/details.asp?ID=1622" rel="nofollow -

54 Atom

/diaries/details.asp?ID=2179" rel="nofollow - 77 Tique

64 X55 Dunphy

Keep it original, Pete
<


Posted By: poecs13
Date Posted: May-15-2019 at 10:28pm
Are there any how-to guides, tutorials or recommended resources? Any special tools required beyond wrenches and socket set? If I'm going to take this on, just want to know what I'm getting into!


Posted By: KENO
Date Posted: May-15-2019 at 11:46pm
I think there's a story about what happened at the dealer but unfortunately you'll never hear it and we won't either

You brought it in with no knock and now it has one

The skeptical little voice in my head says there was some human error involved in this happening right after an oil change and maybe the knock is from a spun bearing 'cause somebody forgot to put new oil in till he heard some funky noises, shut it off and by then the damage was done. Then put the new oil in and tell the customer he has a bad knock.

Hopefully the 2000 dollar quote is to tear it down completely and inspect/ rebuild everything or you may be in for a surprise or 2

Hopefully too, I'm all screwed up and totally out to lunch but like the first sentence says, I don't think you'll ever know what really happened.



Posted By: 63 Skier
Date Posted: May-16-2019 at 12:29am
I don't know Buxton, but busy new boat dealers don't really want this kind of work, it ties up a ton of time that can be spent on things they view as more profitable. I'd definitely pull the engine yourself, it is not hard and I'd recommend you get a mechanically inclined friend to lend a hand, that way when putting it back in you'll have "backup" in terms of any doubts you have. A reputable rebuilder will do a good job, I'm guessing you'll spend more than $2,000, maybe it turns into $3,000, but a 206 in good shape is well worth it IMO. And you know from experience what a great engine that is.

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'63 American Skier - '98 Sport Nautique


Posted By: MrMcD
Date Posted: May-16-2019 at 1:34am
Thinking more about your failure all we know is it hydrolocked. It may have been water and not fuel causing the hydrolock situation.   Exhaust manifold failures have caused water in these engines before. Better have them checked and ruled out as a cause.
How many hours are on this engine? If under 700 I would patch it not rebuild it.
You need a new connecting rod and a gasket set not a rebuild unless there is more to this story.   Has water been found in your oil?
Was this engine overheated at some point?
If the answer is no to these questions just get it fixed.
When they pull the head off, yes one head on the one bad side they will see if it is fuel or water in there and you will know more.
Pulling the engine, if you have a hoist and a good set of tools with basic knowledge.
1-3 hours. Truck it over to a machine shop, have them pull the piston and rod, inspect the parts and put it back together Probably 4-6 hours to put it back in since nothing ever goes back as easy as it comes apart and get back on the water.

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Posted By: 63 Skier
Date Posted: May-16-2019 at 1:42am
Mark, in an above post Charlie said:

"When I purchased the boat in June 2017 it had 415 hours and it is now up to 485. Way too young to be requiring a rebuild if it was cared for properly all it's life, right?"

So he doesn't have the benefit of knowing if it was overheated, or any other past problems. I'm thinking you pull the engine, hand it off to a rebuilder, after partial tear down get their opinion on what they see and decide whether to do a full rebuild then or not.

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'63 American Skier - '98 Sport Nautique


Posted By: Smithfamily
Date Posted: May-16-2019 at 9:33am
If youre pulling the engine out rebuild right and KNOW what your putting back in. If you sell as-is, you will take a bath. If you fix it and the wife still has doubts, sell it and move on. I bought my 92 with a blown head gasket. Based upon the (Outrageous) dealer repair quote given to the previous owner, I based my purchase price. (Running 92 minus the estimate was established value) I pulled the motor with help, (LOTS of Help HERE!) had it rebuilt ($2,000.00 in 2010) put it back in, and went skiing. Still skiing. You can do it.

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Js


Posted By: phatsat67
Date Posted: May-16-2019 at 10:05am
I would be a fan of handling this rebuild yourself. First reason being, if there was something funky going on at Buxton a reputable machine shop will tell you the rod is A-ok and the bearing was spun or damaged due to lack of oil (would then be their fault).

I would have them document the engine serial number and possibly casting numbers on their work order before you sign it refusing their work.

Most of your external engine parts are very easy to remove/install and could be handled by anyone somewhat mechanical. The more you pull off before going to the machine shop the less money you will spend. You can clean up/prep all of the pieces you keep at home at your leisure. Label all wiring you remove so you remember where it goes.

The only part that will require a special tool would be distributor installation and timing adjustment on this engine. (I forget the procedure now for an EFI 5.7)

When the engine goes back in there are plenty of shaft alignment threads and even a video by Pete himself so that would be easily handled when you understand the concept.


Posted By: KENO
Date Posted: May-16-2019 at 10:30am
Originally posted by phatsat67 phatsat67 wrote:


The only part that will require a special tool would be distributor installation and timing adjustment on this engine. (I forget the procedure now for an EFI 5.7)


Since he has a 6.0 ZR6 engine would that maybe make this statement "not exactly right"?


Posted By: phatsat67
Date Posted: May-16-2019 at 10:44am
Whoops, thought I saw 5.7. Even easier then !


Posted By: samudj01
Date Posted: May-16-2019 at 11:44am
Take lots (and then more) pics before teardown and during. You will love them in a few weeks or months. These guys will get you through it. They did us well but there is no substitute for pics of how it was before!

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78 Ski Tique, 72 Skier w/302's, 93 SN w/351 & 17 GS22 w/zr409
Previous - 99 Sport Nautique w/GT40 and 87 Martinique w/351


Posted By: gt40KS
Date Posted: May-16-2019 at 3:45pm
If you are even a little mechanically inclined the R &R of your engine is fairly straightforward - as was said biggest issue may be hoisting it out of the boat. And yes, take lots of pics - before unplugging/ disconnecting and after as well.
I'd certainly remove as much of the interior as possible in & around the work area since it doesn't take much to damage the skins. I'd also cover your carpet with a poly tarp and tape it down as best you can - oil & grease can and will soak right through canvas.

Finally, be sure you get an exact explanation, in writing, of everything the machine shop is actually going to do to the engine. $2k seems really cheap for everything that should be done. Or at least as Ken indicated, they should be tearing it completely down to CHECK for spun bearings and the like. That in and of itself is a lot of labor. My 2 cents

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JCCI
1995 Ski Nautique GT40


Posted By: MrMcD
Date Posted: May-16-2019 at 7:01pm
485 hours, the inside of that engine should be nearly new if it was well cared for.
The guys are right, you won't know till someone qualified opens if up.
A rookie opening it up may not notice what actually happened in there.

If it is just a bent rod, that is all I would replace but then you need to find what caused it or it will happen again, with a rebuild or not the cause is still in that engine unless Ken is correct and a mechanic made a big boo boo causing this issue.
Tear down will tell you everything.
I have a lot of internal engine experience, If I pulled the oil pan and the bearing was perfect on this bad connecting rod I would not even inspect the others. They will be in the same shape. If that rod did spin a bearing then absolutely you are tearing it all the way down.
When the head comes off the gasket can be examined to see if it had failed letting coolant in to that cylinder. Read the piston head, the carbon build up or lack of carbon build up will tell you how that cylinder was running. When the head comes off all 4 cylinders should look the same. One bent rod that knocks will leave witness marks on the head and piston top where they have been touching.
If that cylinder had fuel leaking or coolant leaking in it will not look the same, it will be much cleaner. Less carbon build up. and may look washed clean.

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Posted By: poecs13
Date Posted: May-22-2019 at 7:19pm
Thank you all for the valuable feedback and input. I've done some reading online and have https://www.amazon.com/gp/product/193249460X/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1" rel="nofollow - this book on the way from Amazon. I've decided that I'm up for the challenge and am going to tackle the pull and teardown.

On a quick browse of Craigslist today, I happened upon https://dallas.craigslist.org/mdf/pts/d/colleyville-gm-ls-60l-lq9-lq4-short/6866512273.html" rel="nofollow - this listing.

Would I be able to do a straight swap and solve my problem? And then part out the stuff that isn't broken on what I have? Or is that just asking for trouble?

Heading into Memorial Day weekend without a working boat is just about killing me and I want to get back on the water ASAP! If I were able to swap these parts in, that would eliminate time spent in the shop and I'd be able to teardown and rebuild the same day, right?



Posted By: KENO
Date Posted: May-23-2019 at 1:34am
Since you really don't know for sure what's wrong with the engine yet, I think I'd get it out of the boat and figure out what's wrong before buying something like that short block.

If your days in Texas last about 96 hours or so, you may get it done in a day

You'll probably spend most of the first day scratching your head, figuring things out, taking pictures,labeling things and getting the engine out and getting into the disassembly process to figure out what's wrong.

I'd also tell myself the lake or river will be way too crowded on the holiday weekend and it wouldn't be a big deal to miss the boating and get everything right the first time instead of rushing through it and missing something and getting to do it all over again



Posted By: poecs13
Date Posted: May-28-2019 at 10:03pm
Been a busy weekend! Built a gantry, pulled the motor, and stripped it down to the long block. Dropping it off at the machine shop tomorrow AM! Thanks all for the words of encouragement, I ran into few issues along the way and documented as the engine came apart. Hoping that reassembly will be just as smooth!

While I was stripping the engine down, I managed to only break one part. I'm not exactly sure what it is though, can someone help identify? It's a small hose that connects the intake manifold to the starboard head near the front end of the engine. Picture shown here:




For your viewing pleasure:

https://youtu.be/ItXcoho8sFg" rel="nofollow - Engine Lifted

https://youtu.be/LIuQhgIi0ik" rel="nofollow - Engine Loaded

Engine before:


Stripped to long block:




Posted By: KENO
Date Posted: July-22-2019 at 8:44pm
it's been a while, how did this turn out?


Posted By: poecs13
Date Posted: July-24-2019 at 1:10am
Hey Ken! Thanks for checking in!

I suppose that I should have mentioned that my wife and I like to escape the Texas heat in June and July and have been up in the northeast. When I dropped the engine off before we left I told them I wouldn't be back for it until August. So the project has had a bit of a hiatus. I expect they'll be working it into their queue soon. I will call in at the end of the week to see if they have a diagnosis and cause which I know we are all curious about!

The plan at the moment is to pick up the engine and reassemble it on August 7. Hope to drop it back into the boat that weekend on the 10th and be back in business.

Resurfacing this post reminds me...was anyone able to identify my broken part in the picture above?


Posted By: KENO
Date Posted: July-24-2019 at 7:50am
Call early, they probably stuffed it in the back corner somewhere and need a reminder

It seems like our Northeast heat lately has been doing a bit of a Texas imitation.


Posted By: KENO
Date Posted: July-24-2019 at 8:27am
I think it's a breather tube that's part of the PCV system.

In the link below is a ZR6 parts manual that might be handy to have.

Look at the diagram on page 8, part 50

http://pcmengines.com/wp-content/uploads/2017/09/imagesL510014.pdf" rel="nofollow - link


Posted By: poecs13
Date Posted: July-24-2019 at 10:48am
Okay, yes, that's definitely the part in question. However, it's not the tube itself that's broken, but the plastic elbow that comes off of the manifold, which you can see in my picture. I will need to double check when I get back to Dallas, but looking at the diagram, I am fearful that the elbow itself doesn't exist as a separate part and the entire manifold would require replacement, which I'm assuming is likely to be an expensive part.

If the elbow doesn't exist as a separate part, could it be repaired with some type of adhesive? Is that tube under any sort of major pressure when the engine is on?


Posted By: KENO
Date Posted: July-24-2019 at 11:03am
It should be relatively easy for your machine shop to replace the elbow in the manifold, either with a press in elbow or by tapping the hole and using a screw in fitting


Posted By: poecs13
Date Posted: July-30-2019 at 7:54pm
Spoke with the machine shop today, it did end up being a bent rod due to hydrolock. They will be re-assembling Monday next week and I'll be picking up on Wednesday. Should be able to put all of the external parts back on and have it ready to drop back into the boat on Saturday. Any words of wisdom/advice on realigning the engine?

The only thing that remains is to identify the cause of my hydrolock. I'm thinking I need to start with the fuel injectors. How does one go about diagnosing those?


Posted By: KENO
Date Posted: July-30-2019 at 8:16pm
In your May 13th post you said that Buxton determined that it was gas in the cylinder, so the injectors seem like the likely starting point.

You must have an outfit locally that can test the injectors and rebuild as necessary or you could buy new injectors. The machine shop should be able to tell you where to go for that.

You know which cylinder and injector caused the problem, but I'd get all 8 tested.

How much are they replacing in the engine just out of curiosity?



Posted By: Treybizttu
Date Posted: July-30-2019 at 8:53pm
What machine shop did you use?



Posted By: poecs13
Date Posted: August-08-2019 at 10:23pm
From the shop that worked the injectors today:
"One of them was stuck wide open. The first set of four took four cleanings before they flowed correctly. The second set took three cleanings to flow correctly. They all seem to be flowing within two to three cc's of each other now. That is about normal and none are sticking open."

So it appears that the wide open injector is the cause of this whole mess. One thing that's a little strange is that Buxton allegedly had all of the injectors cleaned (and one fully replaced) last summer. Do I need to look at just replacing all of them? What is the life expectancy of fuel injectors?

Trey, ended up going with Wells Cylinder Heads in Midlothian. Jamie owns the shop and was really patient in explaining the process and answering a ton of newbie questions. Educating the customer goes a long way with me. They did a full rebuild replacing everything except the crankshaft and camshaft.

Cautiously optimistic that I'll be skiing this weekend. Fingers crossed!


Posted By: KENO
Date Posted: August-08-2019 at 10:30pm
Well at least you know the cause now and it's fixed.

It sounds like the injectors are all good following the cleaning.

I'd verify with the shop that they don't need to be replaced following the cleaning

Get to work on it, it Thursday night


Posted By: phatsat67
Date Posted: August-09-2019 at 10:27am
Sounds like you have a fuel quality issue with wherever you get it? Injectors don't really fail all that often. I would consider a swap of where the fuel comes from or an additive every few tanks or so to keep those clean and lubed up.

On my carby boats I try to run one can of Seafoam a season in one tank just to keep them clean. I haven't really ever had issues but the only thing I have seen keep a snowmobile carb clean was Seafoam.

I would look at an additive that had some type of lubricity for the fuel system.


Posted By: poecs13
Date Posted: August-09-2019 at 11:16am
Fuel quality is an interesting thought...

The PCM manual makes a pretty big deal about ethanol free gasoline. How mission critical is that? Frankly, the only place I was able to find that has ethanol free gas may not have the newest tanks and plumbing.

Fortunately a Sam's Club has recently started supplying ethanol free gasoline so I will definitely switch over to picking up from there.

Is staying ethanol-free important for these motors?


Posted By: phatsat67
Date Posted: August-09-2019 at 11:27am
If they say so I would assume the seals and such aren't ethanol compatible.

I don't run it in my Carb boats now but I never had issues with it degrading things but they have all been updated to newer fuel lines/carb gaskets and seals etc.


Posted By: 8122pbrainard
Date Posted: August-09-2019 at 11:28am
Originally posted by poecs13 poecs13 wrote:

Fuel quality is an interesting thought...

Is staying ethanol-free important for these motors?

Originally posted by KENO KENO wrote:

Originally posted by 8122pbrainard 8122pbrainard wrote:

Originally posted by tryathlete tryathlete wrote:

Originally posted by 8122pbrainard 8122pbrainard wrote:

Originally posted by tryathlete tryathlete wrote:

I ran only ethanol free premium always because I don’t like what happens to ethanol over the winter even with stabil. Why risk it? Ethanol is junk.

I've run ethanol in everything since it's inception and haven't had one problem. It's great stuff.


Hope you’re not serious. Maybe just run straight ethanol then Pete. Great stuff!

Peter,
I'm very serious. Again, I've used it since it's inception and NO problems.


You know I hate to agree with you Pete (Brainard), it really pains me at times

But I'm feelin' real pained right now since I completely agree with your ethanol experiences all year round. And I'm being serious.

I'm talking about today's gas with 10% ethanol No issues





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/diaries/details.asp?ID=1622" rel="nofollow -

54 Atom

/diaries/details.asp?ID=2179" rel="nofollow - 77 Tique

64 X55 Dunphy

Keep it original, Pete
<


Posted By: tryathlete
Date Posted: August-09-2019 at 11:46am
Pete, pure gasoline is better than any hybrid mixed with biofuels and the reasoning for blended ethanol fuels makes no economic or environmental sense except to farmers who grow corn for ethanol.

I think you should consider supporting your passion for biofuels by running E-85. Its 105 octane and you could run insane compression ratios!

In all seriousness, I have never had a fuel problem with an automobile. It’s just our boats and small engines that may have fuel sitting in them for days (and months in winter) and ethanol fuels are less stable than pure gasoline. It’s probably better to drain and use than to store E-10 over our northern winters.


Posted By: Gary S
Date Posted: August-09-2019 at 11:56am
Originally posted by poecs13 poecs13 wrote:



The PCM manual makes a pretty big deal about ethanol free gasoline. How mission critical is that?   


PCM has a history of putting that stuff in their manuals. It’s their lawyers covering their backs. In the late 80’s they told you not to use unleaded gasoline when it already had been fazed out.

-------------
http://www.correctcraftfan.com/diaries/details.asp?ID=1711&sort=&pagenum=1&yrstart=1966&yrend=1970" rel="nofollow - 69 Mustang HM SS
95 Nautique Super Sport


Posted By: MrMcD
Date Posted: August-09-2019 at 3:24pm
Glad you are makng progress. I add a quart of Tranny Fluid, standard ATF to a full tank of gas at the beginning of every year. It helps clean and lubricate injectors.   It is not recommended because it is not EPA approved. Talk to any old diesel mechanic and they will tell you it has been used for years for this purpose.
I first heard of this in the 1980's, something was changed in diesel fuel and they started having injector issues everywhere. Adding the ATF lubricated and protected the injectors against these failures.
On my fuel injected vehicles if they get an odd idle issue I first add the ATF to the gas tank and many times the idle issue goes away for good. You need to run the tank of gas through the engine to see results.
If you doubt the effectiveness of ATF, next time your hands are really greasy pour a little ATF on them, it will break down the grease as fast as a good hand cleaner but it also has lubricating ability. Don't actually do this as the AFT can will tell you it is bad for your health to have ATF on your skin but it does a nice job cleaning and lubricating injectors.
It is good preventative maintenance for a fuel injected engine. You will never detect any smoke out the exhaust or any other effect from running the ATF.   I have used this on our BMW's, Chevy's, Fords, my son's Audi.   Just once a year or so for preventative maintenance.

-------------


Posted By: Faceplant
Date Posted: August-09-2019 at 11:28pm
I do the ATF jingle in my Detroit diesel as well .

-------------
Feels like I am hanging 10 but in reality - probably hanging 6.


Posted By: poecs13
Date Posted: August-11-2019 at 8:19pm
I can hardly believe it, but I had a VERY smooth install and we had it back on the water yesterday. Thanks to all for the words of encouragement and support, I saved several thousand dollars in shop labor by tackling the bulk of this project myself. Couldn't have done it without the wisdom of CCF!

The only issue that remains to tackle is that it is still exhibiting the exact same flooding problem that occurred prior to the bent rod. Would REALLY like to get this resolved so I don't have to repeat this project. As a reminder: the engine will start perfectly on a cold start. If restarting the motor after being off for ten to fifteen minutes, it will crank and crank but will not start until the throttle is moved to WOT, which means that we are flooding somewhere.

I pulled the boat home to Dallas last night intending to do some testing today in the drive way. Oddly enough, I could not re-create the problem today in the drive way. I would run the engine, stop it for 15 minutes, and then it would start perfectly again. Granted, I only idled it in the driveway, it was not under any sort of load or increased RPMs. The only other thing that has changed since yesterday is that I re-filled the gas tank on my way home from the lake. It only had about a quarter tank left.

I did get a fuel pressure gauge and did a leak down test. Results were consistent three separate times and are as follows:

62PSI with engine on @ idle
56PSI, 0 minutes after engine off
50PSI, 2.5 minutes after engine off
44PSI, 5 minutes after engine off
38PSI, 10 minutes after engine off
34PSI, 15minutes after engine off

I was not able to find any specific info regarding what to expect from the ZR6 fuel pressure. Are these specs available anywhere? Does this seem like a normal reduction in pressure following the engine turning off?

My plan for tomorrow is to try to re-create the problem again on a lake. If it shows, I will probably pull the injectors and have them re-tested again to see if one of them has failed again already. If everything is good tomorrow, chock it up to old gas that has been crying in the tank all summer wishing it were being used? Any other ideas on what could be creating the flood?


Posted By: Treybizttu
Date Posted: August-15-2019 at 1:02pm
Any progress?

I'm out of town this week but local to you if you need a hand.


Posted By: JoeinNY
Date Posted: August-15-2019 at 1:20pm
I hate to spend other peoples money - but I would not put one more penny into those injectors pick up new set and go skiing. Often times there are aftermarket alternatives that are cheaper than the automotive oem. Certainly don't pay PCM prices but get you some new crispy crisp injectulators.

-------------
http://www.correctcraftfan.com/diaries/details.asp?ID=1477 - 1983 Ski Nautique 2001
1967 Mustang 302 "Decoy"
http://www.youtube.com/watch?v=cO5MkcBXBBs - Holeshot Video


Posted By: phatsat67
Date Posted: August-15-2019 at 1:24pm
Agree with Joe, the only way an EFI engine can flood while off would be injectors. May also be possible to leak pressure out of the fuel pressure regulator if it uses manifold vacuum as the signal. Otherwise that's about it.


Posted By: Gary S
Date Posted: August-15-2019 at 2:27pm
+2 And if one is known to have started acting up you don’t want it to lean out and melt a new piston either.

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http://www.correctcraftfan.com/diaries/details.asp?ID=1711&sort=&pagenum=1&yrstart=1966&yrend=1970" rel="nofollow - 69 Mustang HM SS
95 Nautique Super Sport


Posted By: poecs13
Date Posted: August-15-2019 at 10:21pm
The injectors were tested again on Tuesday and #1 had failed entirely, stuck wide open, so that's the culprit.

I spent the rest of the day trying to track down the automotive equivalent to no avail. I called three separate PCM dealers and no one could tell me how to cross-reference the part. The closest thing I was able to find in an auto parts store looked identical, except that it had two holes in the bottom vs my injectors having four. If anyone can fill me in on how to properly cross-reference the part, I would be grateful! From what I can tell, the 2005 ZR6 is based on GM's LQ4 model of the LS series. There are no identifying marks or model numbers on the injectors themselves. I've been searching by trying to find fuel injectors for a 2003-2005 Chevy 2500HD pickup. Any other ideas?

So I have a brand new PCM injector on the way from Miami Nautique to the tune of $200. I love the idea of replacing the other seven, but the $1400 price tag for that is a bit tough to swallow. How important is it that the other seven are replaced?

I will get back to town Saturday morning, install the new injector, and hopefully close the books on this one.


Posted By: DHMcFadin
Date Posted: August-15-2019 at 10:32pm
Here you go:
https://www.mniboats.com/PCM-Fuel-Injector-6-0L-8NH-p/ra087009.htm

New OEM Fuel Injector Set of (8) For Chevrolet and GMC V8-6.0L https://www.amazon.com/dp/B019EHCV38/ref=cm_sw_r_cp_api_i_vOFvDbTR2ZG40

https://www.summitracing.com/search/part-type/fuel-injectors/make/chevrolet/engine-size/6-0l-364

Lots of options. Might be worth your time to replace all 8.

-------------
1999 Longhorn Nautique
1995 Nautique Super Sport
https://www.instagram.com/longhorn_nautique/" rel="nofollow - https://www.instagram.com/longhorn_nautique/


Posted By: poecs13
Date Posted: August-15-2019 at 10:41pm
https://www.mniboats.com/PCM-Fuel-Injector-6-0L-LQ4-p/ra087008.htm%20" rel="nofollow - This is the PCM one that my boat needs.

What I'm looking for is an automotive equivalent from ACDelco or the like for cheaper than PCM's $200 a piece.


Posted By: Gary S
Date Posted: August-15-2019 at 10:45pm
Originally posted by JoeinNY JoeinNY wrote:

    Often times there are aftermarket alternatives that are cheaper than the automotive oem. Certainly don't pay PCM prices but get you some new crispy crisp injectulators.


Like Joe says there has to be other alternatives. Here for example are ones for Fords-
https://www.skidim.com/prodinfo.asp?number=RN0154" rel="nofollow - 200 dollar each PCM injector

https://www.summitracing.com/parts/fms-m-9593-lu24a?seid=srese1&gclid=Cj0KCQjwhdTqBRDNARIsABsOl9_Jq8pDzWDWIU98Ibz_fhFVG5jgqZa8hNx4PubKBfvVYDpYHhZTwREaAnDIEALw_wcB" rel="nofollow - 215 dollar set of 8 Ford motorsport injectors

Just need to find the spec's of your GM injectors,PCM for sure did not make them

-------------
http://www.correctcraftfan.com/diaries/details.asp?ID=1711&sort=&pagenum=1&yrstart=1966&yrend=1970" rel="nofollow - 69 Mustang HM SS
95 Nautique Super Sport


Posted By: Gary S
Date Posted: August-15-2019 at 10:54pm
Originally posted by poecs13 poecs13 wrote:

From the shop that worked the injectors today:
"One of them was stuck wide open. The first set of four took four cleanings before they flowed correctly. The second set took three cleanings to flow correctly. They all seem to be flowing within two to three cc's of each other.


Your injector shop should be able to advise you on their size and alternatives

-------------
http://www.correctcraftfan.com/diaries/details.asp?ID=1711&sort=&pagenum=1&yrstart=1966&yrend=1970" rel="nofollow - 69 Mustang HM SS
95 Nautique Super Sport


Posted By: poecs13
Date Posted: August-15-2019 at 11:10pm
%20https://www.amazon.com/dp/B07DWN8L4N/ref=sspa_dk_detail_0?psc=1&pd_rd_i=B07DWN8L4N&pd_rd_w=I2Z4S&pf_rd_p=8a8f3917-7900-4ce8-ad90-adf0d53c0985&pd_rd_wg=7DjtS&pf_rd_r=QG5C2BBDFAJ7XQPRGKHM&pd_rd_r=4ef79086-5bde-4313-8697-4ef0dfadd0c4&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUEyNDJDWFlRNjJWWU02JmVuY3J5cHRlZElkPUEwNzc2MTU1MzBLNklHOEVWWTFONCZlbmNyeXB0ZWRBZElkPUEwMDQxMDQ5MkJMUTk4V1ZRSEpFNyZ3aWRnZXROYW1lPXNwX2RldGFpbCZhY3Rpb249Y2xpY2tSZWRpcmVjdCZkb05vdExvZ0NsaWNrPXRydWU=" rel="nofollow - A set of 8 for $50

Only ones I've found so far with four holes in the bottom. At that price point should I be at all concerned with the quality of the part or just go for it?


Posted By: poecs13
Date Posted: August-15-2019 at 11:11pm
I figured the injector shop would be able to give a recommendation, but I said the word "marine" and their eyes glazed over.


Posted By: DHMcFadin
Date Posted: August-15-2019 at 11:13pm
Originally posted by poecs13 poecs13 wrote:

I figured the injector shop would be able to give a recommendation, but I said the word "marine" and their eyes glazed over.


Marine doesn’t matter. Is a standard GM 6.0 injector.

-------------
1999 Longhorn Nautique
1995 Nautique Super Sport
https://www.instagram.com/longhorn_nautique/" rel="nofollow - https://www.instagram.com/longhorn_nautique/


Posted By: poecs13
Date Posted: August-15-2019 at 11:44pm
Right, but apparently they come in a two or four hole variety, does that make a difference? The engine currently has the four hole version.


Posted By: Gary S
Date Posted: August-15-2019 at 11:56pm
Originally posted by poecs13 poecs13 wrote:

At that price point should I be at all concerned with the quality of the part or just go for it?


With what you just spent on the engine rebuild don't now get cheap on the injectors. I know nothing about GM's other than to put my key in my truck and go but I would find a name brand injector,those seem awful cheap.
You know it can go horribly wrong the other way too- here is a melted piston from a GT40 that ran lean on #8

http://imgbox.com/Hf190EH8" rel="nofollow">

-------------
http://www.correctcraftfan.com/diaries/details.asp?ID=1711&sort=&pagenum=1&yrstart=1966&yrend=1970" rel="nofollow - 69 Mustang HM SS
95 Nautique Super Sport


Posted By: Gary S
Date Posted: August-16-2019 at 12:08am
Originally posted by poecs13 poecs13 wrote:

Right, but apparently they come in a two or four hole variety, does that make a difference? The engine currently has the four hole version.


Does on a Ford,the high hp ones have the 4 hole. Just to be safe I would not change

-------------
http://www.correctcraftfan.com/diaries/details.asp?ID=1711&sort=&pagenum=1&yrstart=1966&yrend=1970" rel="nofollow - 69 Mustang HM SS
95 Nautique Super Sport


Posted By: DHMcFadin
Date Posted: August-16-2019 at 12:09am
Grab a set of either GM label or Delphi injectors. Can be found easily online. Get a set of 8 so they all match.

-------------
1999 Longhorn Nautique
1995 Nautique Super Sport
https://www.instagram.com/longhorn_nautique/" rel="nofollow - https://www.instagram.com/longhorn_nautique/


Posted By: DHMcFadin
Date Posted: August-16-2019 at 12:17am
Grab a set of either GM label or Delphi injectors. Can be found easily online. Get a set of 8 so they all match.

-------------
1999 Longhorn Nautique
1995 Nautique Super Sport
https://www.instagram.com/longhorn_nautique/" rel="nofollow - https://www.instagram.com/longhorn_nautique/


Posted By: gun-driver
Date Posted: August-16-2019 at 9:50am
Originally posted by Gary S Gary S wrote:

With what you just spent on the engine rebuild don't now get cheap on the injectors. I know nothing about GM's other than to put my key in my truck and go but I would find a name brand injector,those seem awful cheap.
You know it can go horribly wrong the other way too- here is a melted piston from a GT40 that ran lean on #8

http://imgbox.com/Hf190EH8" rel="nofollow">


Come on Gary a little emery cloth some pig mat n polish and slap it back in the hole.



Posted By: Gary S
Date Posted: August-16-2019 at 4:40pm
I’m gonna use some JB Weld there Paul- it’s got weld right them there in its name

-------------
http://www.correctcraftfan.com/diaries/details.asp?ID=1711&sort=&pagenum=1&yrstart=1966&yrend=1970" rel="nofollow - 69 Mustang HM SS
95 Nautique Super Sport


Posted By: poecs13
Date Posted: August-17-2019 at 4:47am
Okay...the “PCM” (Delphi) one arrived from Miami Nautique and it has...you guessed it...TWO holes.

So now what? I’m thinking all eight should match? Were the original injectors 2 hole and someone switched them to 4 at some point? Sufficiently confused at this point. Am I making a mountain out of a mole hill with the number of holes?


Posted By: Treybizttu
Date Posted: August-17-2019 at 6:21pm
I would want them to match. I still doubt the number of holes needs to match as long as the volume/pressure matches...


Posted By: KENO
Date Posted: April-21-2020 at 11:49am
Poecs13

Since you've been logged on a few times lately, is there a happy ending to this story?


Posted By: poecs13
Date Posted: May-04-2020 at 10:32am
Ken,

Thanks for checking in, I've been meaning to get back on here to write an update. This was the kick I needed.

I wish I had better news, but I'm still dealing with the same hot start issue that I chronicled %20http://www.correctcraftfan.com/forum/forum_posts.asp?TID=43319&title=strange-flooding-condition" rel="nofollow - here before the hydrolock and engine rebuild. Hard to believe that it's been almost two years and I still haven't solved the problem...

It takes one crank to start the engine cold, no problem. After the engine is warm, if it sits for more than ten minutes after shut off, it is flooded and I have open the throttle wide open to clear it to restart.

On the post referenced above, Jody suggested replacing the air temp sensor in the flame arrestor, but all I have near my flame arrestor sensor-wise is a Throttle Position Sensor and an Idle Air Control Valve. Unless one of them also has a temperature sensor?

I am open to any and all suggestions on this one. My wife is ready to trade the boat in. She doesn't want to go another summer with a non-functioning boat and is (rightfully) fearful of repeating the hydrolock episode from last spring if we continue to run as is.


Posted By: KENO
Date Posted: May-04-2020 at 6:14pm
I think you don't have an IAT sensor

The link below is to a PCM manual that covers more than one engine but your 6.0 is one of them.

It's a 337 page download and if you go to page section 2 you'll find lots of sensor info and the 6.0 doesn't seem to have one. The 5.7 for example has a combined MAP/IAT sensor but in a couple of places it says your 6.0 doesn't. and doesn't have an input to the computer unless the functions are combined and they don't talk about it.

All kinds of good GM fuel injection info in the manual

https://www.pirate4x4.com/tech/billavista/MEFI/MEFI%204%20&%204B%20DIAGNOSTIC%20MANUAL%20%28L510005P%29.pdf" rel="nofollow - link


Posted By: poecs13
Date Posted: May-04-2020 at 6:55pm
Ken,

Thanks for the manual! I hadn't come across that one yet, but it is super helpful.

However, the manual states that the combo MAP/IAT sensor only exists on the 5.0/5.7 motors. On the 6.0, it's only a MAP sensor. Is the MAP sensor still the potential culprit in this case?


Posted By: KENO
Date Posted: May-04-2020 at 8:30pm
Originally posted by poecs13 poecs13 wrote:

Ken,

Thanks for the manual! I hadn't come across that one yet, but it is super helpful.

However, the manual states that the combo MAP/IAT sensor only exists on the 5.0/5.7 motors. On the 6.0, it's only a MAP sensor. Is the MAP sensor still the potential culprit in this case?


Well at least we agree on the way we read the manual

The first link below is the parts manual and that lists no IAT sensor either.

The second link is to a PCM MAP sensor for your engine. With a little shopping you can find a generic replacement for half the price if you're so inclined.

It could be a cause of the issue but without the diagnostic tools it's kinda a crap shoot

https://www.planetnautique.com/CorrectCraftManuals/2005/PCM056Lparts.pdf" rel="nofollow - link

https://www.nautiqueparts.com/product/map-sensor-pcm-6-0-8-1-liter-engines/" rel="nofollow - link


Posted By: MrMcD
Date Posted: May-04-2020 at 9:08pm
Sounds to me like the injector issue was never fixed. 4 hole or 2 hole does not matter but what does matter is the gallons per hour flow and a quality build.
Many GM drivers tune for more horsepower with the LS engine blocks.   A common upgrade is to replace standard injectors with new injectors that have a higher gallon per hour flow rate to keep up with the other performance mods they make.
The only source for fuel in the intake is your injectors, if you are flooding they are not holding the fuel.   
Opening the throttle wide open while starting in modern fuel injected engines will shut off your fuel flow, this is an automatic built in process to help clear a flooded engine.
The fact you have to do this to start does again point to injectors as your problem.
I would not change any other parts till you fix this issue.
Yours failed at a very young age, not sure why but maybe the previous owner ran a bad injector cleaner through your system and damaged them.   I would replace all 8 before you do more damage to your brand new engine.   
GM does not make fuel injectors, they are probably OEM Bosch or Denso brand sold by GM.   Take a close up picture of your injector, the part number is usually printed right on it.
Many companies sell OEM type injectors that will swap in with zero issue.   I would do some reading on the Camaro and Corvette forums to see what brand those guys are happy with, I would not think twice about Marine, not important for this part.
If your OEM injectors are 24 lb injectors I would stay close to that number for your boat, if you find 26 or 28 lb injectors for a good price use them.   A small change will not affect you but stay with the same if possible. Do some reading or ask questions and make sure the new injectors are E85 compatible, that would allow more fuel choices in the future.
How does the new engine run?   I hope it makes you happy when it is running.

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Posted By: MrMcD
Date Posted: May-04-2020 at 9:17pm
Injector reading for the LS engines: https://www.lsxmag.com/tech-stories/injector-specs-gm-fuel-injector-identification-and-cross-reference/

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Posted By: zwoobah
Date Posted: May-05-2020 at 12:34pm
Pull your fuel rails, leave the injectors and fuel lines attached. Put a thick rag topped with clean paper towels beneath each injector tip. Turn on the key to prime the fuel system, then turn the key off. Come back after an hour and see which injector is leaking down - you'll see gas soaked into the paper towel below the bad injector.

I had this problem on a BMW 330i. Car ran perfectly but was miserable to get started. Bad #4 injector caused the problem.

-------------
1968 Mustang 16 - 351W powered


Posted By: poecs13
Date Posted: May-09-2020 at 6:09pm
Only had a few hours at the lake today, so didn't get to do everything I wanted to or test thoroughly, but I think some progress made:

An acquaintance theorized that the excess fuel may be the result of a blocked return line from the Fuel Control Cell back to the tank. The excess fuel has to go somewhere, so probably into the rails and out the injectors. Also the only place for pressure to be relieved after turning off the engine. He suggested taking some extra fuel line and running the boat off of a five gallon can. When I tried this, it miraculously solved the hot start issue.

I ran out of time, and still intend to double check the injectors. But I'm cautiously optimistic that if I replace the return fuel line that we can finally put this thing to bed. I was able to blow through the line without too much resistance, but maybe the interior has deteriorated so there isn't adequate flow back to the tank? Does this seem plausible as a cause and viable solution?

My next trip out will be longer so I will have more time to thoroughly test this solution and double check the injectors.


Posted By: Orlando76
Date Posted: May-09-2020 at 10:44pm
What would you do... for a Klondike Bar?

-------------
Please support The Cystic Fibrosis Foundation
1976 Ski Nautique 351 Escort
1993 Ski Nautique purple and black 351 HO PCM


Posted By: tryathlete
Date Posted: May-09-2020 at 10:57pm
If your injectors are not leaking and the tail isn’t over pressure I don’t see how the fuel gets into the cylinders unless the injectors are leaking or the fuel pressure Somehow rises after the pump is turned off.

Test and Replace injectors.


Posted By: gun-driver
Date Posted: May-10-2020 at 4:45pm
Originally posted by poecs13 poecs13 wrote:

I was able to blow through the line without too much resistance, but maybe the interior has deteriorated so there isn't adequate flow back to the tank? Does this seem plausible as a cause and viable solution.

No
if you can blow though it fuel can flow through it. I’m not very familiar with the Chevy system but I would assume there has to be a pressure regulator on the return line, that’s where I would start.


Posted By: poecs13
Date Posted: August-15-2020 at 6:53am
So this story has finally drawn to a close, and thankfully a happy ending! Actually resolved the weekend of July 4, but of course with the site crash, no way to update here!

You guys were right, it did end up being a bad injector. Which one? I have no idea because I just replaced all eight at once. But the engine no longer floods ten minutes after shutdown. As a matter of fact, it runs just about perfectly now.

Many thanks to all for your advice and input! CCF is truly an invaluable resource!

Charlie


Posted By: gun-driver
Date Posted: August-16-2020 at 11:26am
Did you end up with 2 hole or 4 hole injectors. Where did you get them, what is the part number, info for the next guy that has this problem would be great.


Posted By: poecs13
Date Posted: September-01-2020 at 7:54am
Great question, forgot about the 2 vs 4 hole thing.

I ended up talking to a guy at Summit Racing about that and he said that from what he knew the two vs four hole thing shouldn't make a difference as the computer would compensate for it. Every injector for the LQ4 that they had in stock was a two-hole (they pulled every compatible injector from the warehouse so we could inspect them). The only place I could find four-hole injectors was on Amazon from refurb manufacturers and the reviews weren't particularly positive. And especially since the official PCM one that I ordered from Miami Nautique was also two hole, I began to think that perhaps the motor was supposed to have the two-hole design in the first place and somewhere in the boat's history someone swapped them for the cheap four-hole injectors on Amazon.

I ended up going with http://https://www.summitracing.com/parts/URM-6988" rel="nofollow - these injectors from Summit. Yes they were remanufactured, but I didn't want to drop $1000 on a set of brand new injectors if it didn't resolve the issue. And I figured if Summit carried them then they must be decent. Since they did end up resolving the issue, I figure that if the refurbed injectors don't last too long, then I can commit to a http://https://www.summitracing.com/parts/ado-17113698?rrec=true" rel="nofollow - new set of AC Delcos.

A little crazy to think that the engine rebuild and all of the heartache could have been avoided with some new injectors. ah well. Live and learn!



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