NOT GETTING FULL POWER
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=405
Printed Date: November-22-2024 at 3:34am
Topic: NOT GETTING FULL POWER
Posted By: Guests
Subject: NOT GETTING FULL POWER
Date Posted: May-25-2004 at 1:00am
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I would first like to thank anyone willing to respond to this post.
OK, here we go. 1993 Sport Nautique. 302 Ford with Electronic Ignition. Symptoms: 1) Out of the hole, the boat bogs a little and then lets loose after a few seconds. It is annoying skiing behind it as you can imagine. Then It runs up to about 4,000 RPMs and wont go any further. Every tenth time, the boat will increase to full speed which is around 5,000 RPM's. Resolution: I thought that this was an obvious accelerator pump issue, so I had the carb rebuilt. At the carb shop they tested it on an engine after being rebuilt and it worked great. They set the idle to about 800 RPM. I took the carb and put it on my boat and the idle was around 1,200. I checked the linkage, it was fine. Testing again the boat had the same symptoms. Bogging and then no top speed. Also, I replaced the spark plugs. Other: Other things I have done are replace the fuel filter, I am now going to replace the fuel pump. I am not sure if I have a fuel problem or if I have some type of electrical issue. Please help ~Steve Martini |
Replies:
Posted By: 66polyhead
Date Posted: May-25-2004 at 1:39am
| You say the boat falls on it's face for the first ten hole-shots. Then it runs good but not at peak? What is the engine temp when you start?, and when it runs, so-so? Sounds like a vacuum leak to me. a cold block and intake is smaller than a hot, or running temp. one. |
Posted By: eCow
Date Posted: May-25-2004 at 2:02am
| I also would vote for the vacume leak. That will give the high idle and running lean will cause power issues also. |
Posted By: Guests
Date Posted: May-25-2004 at 2:19am
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I agree about vacuum. But where the heck are the vacuum lines on this engine? I cannot find one? It does not matter whether the boat is hot or cold.
To elaborate, the boat stumbles to reach full power which most of the time is only 4,000 RPM instead of the full 5,000.00 |
Posted By: Rick
Date Posted: May-25-2004 at 3:48am
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Check around the carb are there any black plugs or covers that look cracked or melted? ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=250&yrstart=1996&yrend=2000%20" rel="nofollow - 2000 Ski |
Posted By: AWhite70
Date Posted: May-25-2004 at 10:59am
| It doesn't have to be a vacuum hose to be a vacuum leak. Check all of the gaskets between the carb and the intake manifold. (i.e. intake manifold, spacer to manifold, and carb to spacer) |
Posted By: marks
Date Posted: May-25-2004 at 1:35pm
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When replacing the gaskets between the
carb, spacer, and intake manifold, should you use a gasket dressing such as RTV or hylomar? |
Posted By: jameski
Date Posted: May-25-2004 at 1:42pm
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If you're using brand new gaskets and you have perfectly flat and clean mating surfaces then you shouldn't need anything. On boats as old as ours, I seriously doubt the above is the case. The bottom flange of the carb is usually slightly warped. I always spray my carb and spacer gaskets lightly with with copper RTV. It makes for more work the next time, but I've never had a vacume leak since I started doing it. ------------- current boat http://www.correctcraftfan.com/diaries/details.asp?ID=1977 - 94 Sport Nautique previous boat http://www.correctcraftfan.com/diaries/details.asp?ID=601 - 78 Martinique |
Posted By: Guests
Date Posted: May-25-2004 at 5:56pm
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Thanks Guys,
I will pull the carb back off, use the copper RTV and reapply. I agree that it does act like a vaccum leak, I just cant find the sucker. Regarding "Check around the carb are there any black plugs or covers that look cracked or melted?" I am a little confused about these? I will check however. |
Posted By: jameski
Date Posted: May-25-2004 at 8:25pm
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One good way to check for vacuum leaks is to spray some starting fluid. If you have a rough idle the vacuum leak will suck in the starting fluid and will smooth out temporarily. Use the long tube on the sprayer and use very small spurts in specific locations to pinpoint the leak.
Steve, your problem could be electrical. Check your charging system and your timing. ------------- current boat http://www.correctcraftfan.com/diaries/details.asp?ID=1977 - 94 Sport Nautique previous boat http://www.correctcraftfan.com/diaries/details.asp?ID=601 - 78 Martinique |
Posted By: 66polyhead
Date Posted: May-26-2004 at 12:59am
| Bingo! Jameski. Spray carb cleaner, ether, anything solvent based, around the carb base, intake manifold, to see if the engine r.p.m.'s change. I use Permatex, "the good stuff" in a caulk gun applicator, on everything I work on, and own. It's great, urethane and polymer rules. If you seal all gasket surfaces, and still have a problem, I would check engine timing, and if you can, take the valve covers off, pull the coil wire off, crank it over and watch all the rocker arms to see if all are rocking properly. |
Posted By: 64 Skier
Date Posted: May-26-2004 at 6:44am
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I was gonna post the idea of using the Starter fluid to find the leak.....BE CAREFULL...I work offshore and we used to do this a lot, but a few years ago the Manufacturers quietly removed it from their Troubleshooting guides.
Jameski said the problem could be Electrical...if so, you have a "source and ignition" so again, be carefull. What type of advance do you have? Vacuum or Mechanical? ------------- 64 Skier 66" HO VTX and 67" HO Triumph http://www.correctcraftfan.com/diaries/details.asp?ID=1071&sort=&pagenum=3&yrstart=1971&yrend=1975 - 71CC |
Posted By: Guests
Date Posted: May-26-2004 at 3:29pm
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Wow, thanks for all of the help. By the way I am out in San Diego in Mission Bay; Salt Water sucks let me tell you. I am from the Finger Lakes region of NY originally where the water is fresh! Much better. Anyway, took her out last night after replacing the fuel pump, reinstalling the carb with some copper RTV. Initially I thought it was fixed, the idle was much better. When I started to give it to her, she began to back fire and would stall out. So, I began to think that since I have gone through the fuel that maybe it is an electrical issue like you suggested. Well I began to look at the plug wires from the spark plugs and they were fine. Then I traced them back to the electrical block (electronic ignition) and found that three out of the 8 were very badly corroded. It was very weird, 5 looked brand new and then three that were right next to each to other looked like they had been sitting in salt water for a couple of months. So, I scraped the rust with a screw driver and tested it out, I got my full speed this time but I still had hesitation and backfiring. But it was better. So I think this is the problem. I am going to replace the spark plug wires. Should I buy PCM factory or will any do from an auto parts store? Also, I have a question about my electronic ignition; I do not think it is factory because I cannot find anything in the service manual about it. All they have is info about non-electrical. I do not know anything about my electronic ignition. It says PCM on the black top where the distributor should be but there is no marking on the black block on the back of the engine where the plug wires run too? Where could I find out about this and would it be an idea to replace it? Any suggestions? Steve |
Posted By: Guests
Date Posted: May-26-2004 at 4:01pm
| Also, I did do the starting fluid technique, after using the copper RTV, there appeared to be no leaks |
Posted By: 64 Skier
Date Posted: May-27-2004 at 1:13am
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I think 66polyhead said to check the timing and I agree.
When starting out, if you have the Holley, the engine goes through (struggles with) two stages. First is running with the idle circuit in the carb and retarded timing...then you hit the gas and...your pumping gas through the accelerator pump, and jets as the advance mechanism kicks in. Lot of things going on that have to be right. If you've re-built the carb and removed that mystery...check your timing and advance. If you still have the vacuum leak it will not allow your engine to advance properly....or the advance unit itself needs repair (pretty rare) ------------- 64 Skier 66" HO VTX and 67" HO Triumph http://www.correctcraftfan.com/diaries/details.asp?ID=1071&sort=&pagenum=3&yrstart=1971&yrend=1975 - 71CC |
Posted By: Guests
Date Posted: May-27-2004 at 2:35am
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But 64 Skier, I have an electronic ignition, there is no way to set the timing on an electronic ignition right? I did not think there was, but if there is I would love to know.
Thanks |
Posted By: 64 Skier
Date Posted: May-29-2004 at 1:27pm
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Just rotate the distributor.
Not sure what type of PCM Electronic Ignition you have, but I'm assuming what you are refering to is one without points. If you'll loosen the bolt holding the distributor in place and rotate, you'll adjust the timing. Of course, you'll need to shoot the light on it to watch the adjustment. Hope this helps you out. ------------- 64 Skier 66" HO VTX and 67" HO Triumph http://www.correctcraftfan.com/diaries/details.asp?ID=1071&sort=&pagenum=3&yrstart=1971&yrend=1975 - 71CC |
Posted By: Rick
Date Posted: May-29-2004 at 2:20pm
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It sounds alot like timing. Take the distributor cap off. Next remove the rotor and the plate where the points/magnetic pickup is mounted. Under that plate is the advance mechanism. If it is mechanical make sure it's not rusted to where it won't advance. I its vacumn make sure pulling a vacunm on the hose moves it and that the hose doesn't leak. It may also be getting caught as it advances. Also you can put a timing light on the engine run it crack the throttle and see if the timing mark moves.Hope this helps. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=250&yrstart=1996&yrend=2000%20" rel="nofollow - 2000 Ski |
Posted By: thevogt
Date Posted: May-30-2004 at 1:34am
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Steve-
Sounds like the Pro-Tec ignition. Same as on my '93 Sport. For a '93 PCM manual, try this link. It is a discussion I started on PlanetNautique awhile back when I was having problems on mine. They came through with a PCM manual that I was able to download. Also, I always used carb cleaner, not ether, to test for leaks. http://www.planetnautique.com/index.php?name=PNphpBB2&file=viewtopic&t=1037 Scroll way down for the link to the download. It has a wealth of info. I don't think there is a change from '93 to '94 on the 302. You could also call Correct Craft and see if they can get you one if this isn't what you want. Hope this helps. Gary ------------- '93 Sport Nautique-351 ProBoss-104 hrs as of 5/15/04 (shame on me) |
Posted By: Guests
Date Posted: May-30-2004 at 4:23pm
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Gary:
Thanks a lot. I will look into all of this. Did you have troubles with yours? Can you set the timing on these things? What is your e-mail? |
Posted By: Rick
Date Posted: May-31-2004 at 3:57am
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Steve I'm in Rancho Bernardo. Email rloomis2@san.rr.com contact me I'll see if I can help ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=250&yrstart=1996&yrend=2000%20" rel="nofollow - 2000 Ski |
Posted By: Guests
Date Posted: May-31-2004 at 2:00pm
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Steve-
Have not had any timing issues with mine, only transmission, steering cable, starter, carburetor, starter solenoid, and raw water impeller. All of these were due to an improperly prepared 4 year layup of the boat and/or normal wear. I have all but the transmission trouble worked out. The trans should be cleared up shortly. My email is thevogt@mac.com. Good luck. Gary |
Posted By: nms1991
Date Posted: May-31-2004 at 8:25pm
| the motor is accually a ford 351 converted by pcm using their protech ignition system. It is like gm's dis system on the 3800 series engine in cars but less sofisticated. yes you can check timing and adjust it but be careful it could cause other problems like burning a piston or a valve if you over advance the timing. I would recomend replacing the plug wires with factory replacements because if you use the wrong type it could cause rfi interferance and cause the system to go into limp mode. skidim should have the wires resonablly priced or any pcm dealer should have them. |
Posted By: Guests
Date Posted: June-01-2004 at 1:00am
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Ok: Well I will adjust the timing carefully and check with Skidim. Thanks for the tip.
What is limp mode. How do I know if it is in that mode or not? |
Posted By: Guests
Date Posted: June-02-2004 at 2:06pm
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Ok,
I read the entire owners manual yesterday and went out and spent about 3 hours with the boat. First problem I had was bad fuel. That solved the the issue with the idle and the skipping at top end. It however did not stop the issue with the flooding and backfiring and stalling when I drop the hammer as if I was going to pull somone out of the water. The timing is simply not advancing like it should. Since this is an Electronic Ignition I see no reason why the timing should be adjusted. I have never touched it therefore it should not be needed to be played with. I have however come to the conclusion that my coil pack is shot. That is why the timing is not advancing like it should, causing a slight backfire and a hesitiation. I wish sometimes this thing just had a good old distributer and some points. Now, where can I get one of these coil packs? Let me know what you guys think of my theory. Steve |
Posted By: docmartini
Date Posted: June-02-2004 at 8:53pm
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CAN I DROP ONE IN FROM A GM 3800 Series? OR DO I HAVE TO GO PAY 5X as much for a marine?
------------- STEVEN MARTINI 70 degress and sunny |
Posted By: nms1991
Date Posted: June-07-2004 at 2:02am
| a coil does not control the spark advance the module under the coil controls the spark advance. you may have to check your knock sensor because it could be causing the system to retard the timing. check your timing at 3600 rpm in the water in neutral, it should be 30 degrees for the 240 hp motor and 26 degrees for the pro boss motor. but also check your spark plugs to make sure they are not fouled out. also is the accelerator pump nozzel still a #25 because you could replace it with a #31 and cure the problem, also make sure the accelerator pump arm is adjusted properly. |
Posted By: Guests
Date Posted: June-07-2004 at 3:05am
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NMS
I had the carb rebuilt by some repudable people. I will call them tomorrow to see what type of accelerator pump nozzel they used. I did check the timing and it is fine. The symptoms are this 1) Engine floods out and stalls if hammer is dropped. 2) Engine misses at top speed. Top speed varies every time that I can get it up that far. Somtimes it is 3600 and others it is pushing 5000, which is fast as heck. When the full throttle is in effect sometimes it will be 3600 and suddenly jump to 5,000 and then drop back down again. 3) The idle fluctuates, sometimes it is fine, other times it stalls when putting it into gear. I will check the pump nozzel. The knock sensor is new. When I disconect it and try to run it it will absolutly not run well. Thanks again |
Posted By: Guests
Date Posted: June-07-2004 at 8:03pm
| Also, this only happens under a load. When tranny is disconnected and sitting it revs fine. |
Posted By: 79nautique
Date Posted: June-09-2004 at 12:06pm
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Steve
I would focus on the ignition system, If it was an induction system problem it would be all the time not intermittent. Also explain your ignition system I'm not sure what type a 93 302 has. Do the spark plug wire attach to a round cap or a retangular box? There are two different types of electronic ignition sytems. One you have to set the time the other you can not. One is a distributor based system with a module, cap and rotor which you have to set base timing then the module controls the advance because it doesn't have mechanical weights, the other is a Direct Ignition System (DIS) which the base time and advance is controled by the computer and crank sensor. I would venture to say you have a distributor based system since I believe the first DIS system for a V8 was done on GM's NorthStar engine in 94 or 95 and ford didn't have one to the best of my knowledge. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=756&sort=&pagenum=1&yrstart=1979&yrend=1979 - 79 nautique |
Posted By: Rick
Date Posted: June-09-2004 at 1:21pm
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I spoke with Steve and he has the DIS ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=250&yrstart=1996&yrend=2000%20" rel="nofollow - 2000 Ski |
Posted By: docmartini
Date Posted: June-09-2004 at 3:20pm
Yes, I do have the DIS.
Here is a picture of it. I got another carb to test out on my boat last night. I will be testing tonight to see if that was my problem. Wish me luck. I do not think this is the issue, however I have to rule it out once and for all. I want to go water skiing so bad. Steve ------------- STEVEN MARTINI 70 degress and sunny |
Posted By: docmartini
Date Posted: June-09-2004 at 3:22pm
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By, the way. PCM does not make this part anymore and they have replaced it with a standard electronic distrbuter system. I would like to know where I could find one of these ------------- STEVEN MARTINI 70 degress and sunny |
Posted By: 79nautique
Date Posted: June-09-2004 at 4:26pm
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It looks like a magnavoz system I would try the auto parts store. If memory serves me right the coils are one big potted assembly and you have to replace all at once but maybe thats just for the V6 applications. The picture looks like it is broke up into two seperate coil packs and you could get by with one. Check the plugs and look for a fouled plug or plugs and trace it back to the coil pack and replace that one first. GM scraped Maganavox's system a couple of years into production as well and replaced it with there own system. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=756&sort=&pagenum=1&yrstart=1979&yrend=1979 - 79 nautique |
Posted By: 66polyhead
Date Posted: June-10-2004 at 12:57am
| Man am I glad mine has breaker - point ignition! But it looks like something I'd like to work on. Good luck! |
Posted By: kenny g
Date Posted: June-10-2004 at 10:17am
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66POLYNOGGIN..i cant find your # call me this week when you get a chance 371-1852. ------------- kenny g |
Posted By: docmartini
Date Posted: July-07-2004 at 8:20pm
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Just wanted to let you know that my problem was the carb after all. Even though I had it rebuilt by San Diego Carburator and they refused to believe that it did not work, it was that after all. I made them give me another carb and know she is running like a top. Thank you for all of your help, I have learned a lot and appreciate the time that you took to help me out. If you are ever in S.D and want to go for a ski, I am your guy. Take care,
Sincerely, Steven Martini ------------- STEVEN MARTINI 70 degress and sunny |
Posted By: docmartini
Date Posted: July-27-2004 at 3:50am
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Well I am back guys.
She is not running like a top anymore. Eric Raymond, (a great guy who let me borrow a 4160) that I met on this listserv. I have tried three carbs and keep getting three different problems. I am still convienced that it is the carb however. I have done numerous checks ont eh iginition system including hooking a timing light up to each spark plug wire and testing them under loads. I think it is possible that I am getting the problems in the fuel system. Some idle good, some idle bad, all have the same top end problem. Sometimes I get full top end speed, sometimes I do not. Dont know what to do. ------------- STEVEN MARTINI 70 degress and sunny |
Posted By: 79nautique
Date Posted: July-27-2004 at 12:00pm
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Check your fuel pressure and make sure it is steady and does not change with rpm, or it changes very little. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=756&sort=&pagenum=1&yrstart=1979&yrend=1979 - 79 nautique |
Posted By: Rick
Date Posted: July-27-2004 at 3:14pm
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Steve you sound like you need a good ski to ease the pain. How about Thursday or Friday? ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=250&yrstart=1996&yrend=2000%20" rel="nofollow - 2000 Ski |
Posted By: 64 Skier
Date Posted: July-28-2004 at 4:16am
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Different Carb's have different jets and Power valve or springs and metering rods so expect different results unless they're all tuned to your engine. Tuning one is not difficult and you can come close at idle with the proper tools. Just learned this the hard way myself.
Whether or not you do it, or someone else, measure your engine vacuum at idle. Knowing Vacuum is more important than the Carb selection. After you get the Power Valve set correctly, then the best way is to try WOT and then try to pull a skiier (recruit a big boy...it's a test!). After you get past this then start checking for color indications on the plugs. Have you mentioned the plug color? A "good" Holley man can do all this in a few minutes. A friend of mine who races will measure engine vacuum to set and also test when the Power Valve kicks in as well as tuning this with the vacuum advance and then the Secondaries. Your Carb Re-builder should be able to do this. If not, he's just another guy with a $2 bottle of carb cleaner and a set of gaskets. ------------- 64 Skier 66" HO VTX and 67" HO Triumph http://www.correctcraftfan.com/diaries/details.asp?ID=1071&sort=&pagenum=3&yrstart=1971&yrend=1975 - 71CC |