GT40
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=31177
Printed Date: April-29-2024 at 2:08am
Topic: GT40
Posted By: AndrewB
Subject: GT40
Date Posted: August-12-2013 at 6:45pm
| Solved. |
Replies:
Posted By: Hollywood
Date Posted: August-12-2013 at 6:57pm
|
So it cranks but no run? ------------- |
Posted By: AndrewB
Date Posted: August-12-2013 at 7:14pm
| Yea cranks but hard//no starting unless wot sorry that was pretty important |
Posted By: lewy2001
Date Posted: August-12-2013 at 9:26pm
|
When it starts with WOT does it take a moment to clear and then run OK? If it does it sounds like it was flooded. Possible leaking injector, check for loss of fuel pressure when engine is off. ------------- If you're going through hell, keep going http://www.correctcraftfan.com/diaries/details.asp?ID=2999" rel="nofollow - 89 Ski <a href="http://www.correctcraftfan.com/diaries/details.asp?ID=5685" ta |
Posted By: AndrewB
Date Posted: August-12-2013 at 9:59pm
| Nope just idles like nothing was wrong I pulled the injectors and they don't seem to leak at all. Primed the rail and not a drop of fuel out pf them until the inkector blew off the rail the second or third prime. |
Posted By: lewy2001
Date Posted: August-13-2013 at 12:09am
|
OK I would start looking at the TPS (Throttle position sensor). The reference section has the GT40 manual and resistance values for the TPS. ------------- If you're going through hell, keep going http://www.correctcraftfan.com/diaries/details.asp?ID=2999" rel="nofollow - 89 Ski <a href="http://www.correctcraftfan.com/diaries/details.asp?ID=5685" ta |
Posted By: AndrewB
Date Posted: August-14-2013 at 12:34am
| Went ahead and tested the tps the voltages were correct based on the chart in the RM. I also noticed when I was checking the injectors the plenum gasket looked wet on the back 4 runners. Went ahead and put a new gasket on after cleaning everything up. Cleaned up the FCC also changed the inline fuel filter that was installed by the previous owner. Someone in the shop at work had mentioned it sounded either like a tps or MAP sensor. So I went ahead and put a new map sensor on just for the heck of it. The cost was $35 from autozone with Toyotas commercial account there. Anywho threw it all back together took the boat out fired up the first try ran it around the lake and she screamed the Perfect Pass showed 5020 RPM and 45MPH where as before i though the boat had plenty of power but I was only seeing 4200 rpm at WOT. I guess we will see this weekend if my issue is fully resolved. |
Posted By: AndrewB
Date Posted: August-15-2013 at 11:54pm
| Well went out to the lake a day early to put the boat in and as usual fired right up when i first put it in. came back down around 30 minutes later and once again cranks but no start. :( Guess I better keep hunting. |
Posted By: lewy2001
Date Posted: August-16-2013 at 8:59pm
|
Sounds like a possible heat soak problem. Can you hear the pumps run for the prime cycle when ignition is switched to on position. This is a great starting point for any non start problems on the GT40. I would also get a pressure gauge to test that it has correct fuel pressure when it will not start. This http://www.correctcraftfan.com/forum/forum_posts.asp?TID=25775&KW=&title=99-sn-gt40-fuel-supply" rel="nofollow - Old GT40 Thread has lots of information that may help. Will it still start if you go WOT? That is the weird part about your non start problem. ------------- If you're going through hell, keep going http://www.correctcraftfan.com/diaries/details.asp?ID=2999" rel="nofollow - 89 Ski <a href="http://www.correctcraftfan.com/diaries/details.asp?ID=5685" ta |
Posted By: AndrewB
Date Posted: August-16-2013 at 10:10pm
| Yea today went out and boat would not run unless I opened the throttle to wot. 20psi the first prime then 40psi as soon as I cranked and no start unless wot. Took it for a hard run ima go down in a little and see if it'll fire after heat soaking. |
Posted By: AndrewB
Date Posted: August-16-2013 at 10:14pm
| I just wanna throw a real curve here. If I were to pull the boat put it in the garage and put it back in the water tomorrow the first startup would not be an issue. |
Posted By: AndrewB
Date Posted: August-16-2013 at 10:55pm
| Well went down boat wouldn't start smacked the IAC a few times and bam fired right up |
Posted By: lewy2001
Date Posted: August-17-2013 at 2:27am
|
The IAC will not stop the engine from starting. May not idle that well but should still start. "Adjusting" (smacking) the IAC should have no effect except if you have a bad electrical connection somewhere. Just to confirm, when it will not start you have approx. 40psi fuel pressure and the pumps are performing there prime cycle. The manual states the fuel rail should maintain within 3 psi of the approx 40psi for 3 minutes. I would jumper the STO and run the pumps for 30 secs to get your initial 40 psi for this leakdown test. ------------- If you're going through hell, keep going http://www.correctcraftfan.com/diaries/details.asp?ID=2999" rel="nofollow - 89 Ski <a href="http://www.correctcraftfan.com/diaries/details.asp?ID=5685" ta |
Posted By: AndrewB
Date Posted: August-17-2013 at 9:14am
| Yea 40 psi and it holds I left the gauge on came down 20 minutes later and still had 38 psi |
Posted By: AndrewB
Date Posted: August-17-2013 at 8:26pm
| I hit other places today and the boats did start kne of then was the tfi module I'm at a loss here |
Posted By: lewy2001
Date Posted: August-17-2013 at 8:59pm
???? Not sure what is going on with that post. Need a better description than that of symptoms. ------------- If you're going through hell, keep going http://www.correctcraftfan.com/diaries/details.asp?ID=2999" rel="nofollow - 89 Ski <a href="http://www.correctcraftfan.com/diaries/details.asp?ID=5685" ta |
AndrewB wrote:Posted By: AndrewB
Date Posted: August-17-2013 at 9:07pm
| Yea sorry about that I was talking to another guy on the boat. I was tapping the coil and the tfi module not very hard but enough to vibrate them. |
Posted By: Bri892001
Date Posted: August-17-2013 at 9:36pm
| Does the boat always Start when you apply full throttle? |
Posted By: AndrewB
Date Posted: August-17-2013 at 9:46pm
| Bri yes everytime wot fires |
Posted By: Bri892001
Date Posted: August-17-2013 at 9:51pm
Then the question is: What is different about the WOT condition? I know some fuel injected cars used to go into a flood clearing mode like a carb'd under WOT. Like, they'll cut fuel to let it clear. Do you get any kind of black smoke or anything when it fires after not firing? What other parameters change under WOT (kind of putting that question out there for lewy and others). |
Posted By: AndrewB
Date Posted: August-17-2013 at 10:07pm
| Tps voltage is different but as far as commanded fuel and spark values I am not sure i have not ran into it in the service manual yet. |
Posted By: Bri892001
Date Posted: August-17-2013 at 10:08pm
|
I'm thinking Coolant Temp Sensor. http://www.skidim.com/prodinfo.asp?number=R020024" rel="nofollow - http://www.skidim.com/prodinfo.asp?number=R020024 |
Posted By: Bri892001
Date Posted: August-18-2013 at 1:08am
|
Why the Coolant Temp Sensor you ask? When this sensor isn't working, the ECU has to assume the engine is cold and makes a richer fuel mixture, kind of like a choke. When the engine is actually cold, this assumption is correct and it starts fine. When the engine is warm, this assumption is NOT correct, and the engine won't start. However, when you give it WOT it overrides the enrichning mode and goes into the flood clearing/less fuel mode which allows it to start. That's my story and I'm sticking to it. |
Posted By: lewy2001
Date Posted: August-18-2013 at 9:52am
|
Easy way to prove that theory Brian break out the multimeter and measure the resistance of ECT when cold and after reaching operating temperature. From my understanding when the engine is in cranking mode it does not read info from the TPS the mixture is controlled by the cranking map that is between 2:1 and 12:1 (air to fuel) depending on engine temp from ECT sensor.  ------------- If you're going through hell, keep going http://www.correctcraftfan.com/diaries/details.asp?ID=2999" rel="nofollow - 89 Ski <a href="http://www.correctcraftfan.com/diaries/details.asp?ID=5685" ta |
Posted By: AndrewB
Date Posted: August-18-2013 at 1:00pm
| Ect sensor checked ok after going a few more pages found out those resistances should be in Kilo ohms and not ohm. |
Posted By: AndrewB
Date Posted: August-18-2013 at 10:39pm
| Ok guys so far thanks to my great friends at auto zone who let me return parts. I have swapped a new tps, new iac, new map. Still the same issue after boat sits will only fire at wot. Today it seemed to stumble on first start not at wot like it wanted to fire but just didn't have enough of something. Then wot I went and fired right up. |
Posted By: lewy2001
Date Posted: August-20-2013 at 1:42am
|
Andrew, I would remove the TPS from throttle body but still electrically connected and see if it is actually having the throttle butterfly open that is helping the restart (correcting an over rich condition). Not the different resistance from the TPS at WOT that is allowing engine to start. It may be a ECM heatsoak problem but I hope not. ------------- If you're going through hell, keep going http://www.correctcraftfan.com/diaries/details.asp?ID=2999" rel="nofollow - 89 Ski <a href="http://www.correctcraftfan.com/diaries/details.asp?ID=5685" ta |
Posted By: AndrewB
Date Posted: August-20-2013 at 2:18am
| Ahh thanks that's a good plan I am also going to check the air charge temp sensor. Which has the same job as the ect also. Ima be out of town for work but ill update this weekend and hopefully have an answer. |
Posted By: AndrewB
Date Posted: August-20-2013 at 2:21am
| And ecm heatsoak doesn't make sense to me. If I were to pull the boat every night it would start every morning without an issue. When I leave it in the water overnight wot is a must in the morning. |
Posted By: lewy2001
Date Posted: August-20-2013 at 3:50am
Are you saying it is different if the boat stays in the water overnight compared to pulled and put on trailer for the evening??? I was understanding that you only needed WOT after the engine had run and then allowed to heat soak with engine cover closed for 20-30 mins. If it requires WOT next morning on a cold engine then that is something different to previous described symptoms. ------------- If you're going through hell, keep going http://www.correctcraftfan.com/diaries/details.asp?ID=2999" rel="nofollow - 89 Ski <a href="http://www.correctcraftfan.com/diaries/details.asp?ID=5685" ta |
Posted By: AndrewB
Date Posted: August-20-2013 at 8:45am
| Lewy I posted the garage info a few posts up. Things that make thr condition happen. Leaving the boat in overnight, running for 5-10 minutes come back down boat is not gunna fire unless wot. If im sitting with friends for a few hours wot ok first start. The odd thing like I said is if I pul the boat and put it back in the next morning first startup would not be an issue. Thanks for all the help you have been giving. |
Posted By: lewy2001
Date Posted: August-20-2013 at 9:02am
|
Andrew, Leaving the boat in the water overnight is a real curve ball. What is different moisture under engine cover, colder, .......? Try the TPS removal and see what happens. I would also purchase the http://www.amazon.com/Equus-3145-Ford-Digital-Reader/dp/B000EW0KHW/ref=sr_1_3?ie=UTF8&qid=1376998121&sr=8-3&keywords=eqqus+scanner" rel="nofollow - Eqqus Ford EEC1V Code reader it is inexpensive and may help if it has any stored error codes or sensor failures. ------------- If you're going through hell, keep going http://www.correctcraftfan.com/diaries/details.asp?ID=2999" rel="nofollow - 89 Ski <a href="http://www.correctcraftfan.com/diaries/details.asp?ID=5685" ta |
Posted By: AndrewB
Date Posted: August-20-2013 at 10:28am
| Ok I'll have to order that. My thoughts were also the variables. Like how much water is in the coolant passages when I pull the boat. I really leaning far away from a fuel issue but the gas in the tank is another thing that is moved a lot, I know very unlikely but could it be a vapor issue. The vent in the tank seems clear as I blew into it. The whole pulling the boat deal is what throws me the most. I'd hate to take it somewhere because they will more then likely throw parts at it and cost me money. I can throw parts myself but at least I can return them. |
Posted By: AndrewB
Date Posted: August-25-2013 at 9:15pm
| Well no codes :( I did find today my primary coil measured in at 1ohm during the no start condition and range is .38-.42 ohms. Possible weak spark on startup then secondary takes over once running? I'm not sure how the ignition system works yet. Guess we will see what happens. |
Posted By: AndrewB
Date Posted: August-30-2013 at 4:12pm
| Well back again I've searched a few times and cannot find the info I'm looking for. Does anyone have wiring diagrams or a repair manual for the actual boat and not the engine. Vince from skidim advised me to check out my keypad and I'm not sure how it works but I'd like to test it. |
Posted By: Bri892001
Date Posted: August-30-2013 at 6:41pm
| Planet Nautique has a few later wiring diagrams that we don't have, but I haven't seen any real good knowledge on those keypads. Although, there has been a couple threads on them. |
Posted By: AndrewB
Date Posted: September-15-2013 at 12:59am
| Thank you everyone for your help especially Lewy. Even though I never physically could catch my injectors acting up I replaced them anyways just out of a good suspicion after i drove the boat 15 feet shut it off came down a hour later and needed to wot to get it to fire. Seems faulty injectors were my culprit. |
Posted By: AndrewB
Date Posted: September-16-2013 at 2:36pm
| ....blah |
Posted By: AndrewB
Date Posted: October-01-2013 at 12:51am
|
As of now I am pretty much shooting in the dark here and using this post to keep track of the zillion things I have done. Condition: Boat fires right up pulling off the trailer. Drive short distance say 100 yards to the dock park the boat come back in about an hour sometimes boat will start and die others boat does not even fire it seems. After some extended cranking plugs are wet. After no start must WOT to get boat to fire then runs good until next long shutdown. I am currently throwing out the overnight cause because it does not seem to offer anything. Seems after first fire then shutdown is the real issue. Tested/Replaced: Fuel Pressue:40psi cranking Map Sensor Fuel Injectors IAC Valve ECT Sensor Ignition Coil Distributor Cap/Rotor Plugs and wires are around 1-2 years old with maybe low runtime.(Have a new set on the way) TFI Module ECM and F/P relays are only 1 year old. Have Injector Pulse while cranking. Have Spark while cranking. |
Posted By: Bri892001
Date Posted: October-01-2013 at 11:29am
| I remember you said you tested the coolant temp sensor, but how did you test it? |
Posted By: AndrewB
Date Posted: October-01-2013 at 12:01pm
| Replaced the ect but also measured resistance before and it was good. For the $10 the sensor costs |
Posted By: JoeinNY
Date Posted: October-01-2013 at 12:15pm
|
Sounds like leaky injector(s) to me ------------- 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: AndrewB
Date Posted: October-01-2013 at 12:32pm
| I replaced the injectors |
Posted By: lewy2001
Date Posted: October-01-2013 at 10:04pm
Andrew have you had a chance to try this yet? ------------- If you're going through hell, keep going http://www.correctcraftfan.com/diaries/details.asp?ID=2999" rel="nofollow - 89 Ski <a href="http://www.correctcraftfan.com/diaries/details.asp?ID=5685" ta |
Posted By: AndrewB
Date Posted: October-01-2013 at 10:07pm
| Lewy I have but I forgot to post the result and dont want to say what it did and did not do I will post back here soon with the results probably wont be out at the lake till this weekend but I want to say YES it did still start at WOT. |
Posted By: skfitz
Date Posted: October-06-2013 at 2:04am
| Sounds like your injunction pulsewidths are too large during hot cranking. Not sure how you'd confirm or fix that on a stock Ford system though. |
Posted By: AndrewB
Date Posted: October-07-2013 at 8:05pm
| Lewy the boat did start with the tps off and WOT. I discovered this weekend with the FPR hose off the boat fired no matter what. It was odd i fired the boat with the hose off then put the hose back on and it chugged like it would barely run until it finally smoothed out. There is no evidence of fuel in the hose but it did smell terrible of fuel. I am thinking the problem is in the fuel system here wether a pump or regulator I am not sure yet. I did apply vac to the regulator and it did hold. |
Posted By: lewy2001
Date Posted: October-09-2013 at 12:09am
Confirms that it is a over rich or flooded fuel issue. If it passed the fuel pressure leak down test and you have replaced the injectors that rules them out. It could be the fuel pressure regulator but that should have also shown up in the leak down test. It maybe somewhat intermittent causing false assumptions. Just because you replaced the ECM 12 months ago does not mean it can not have a new problem. But I hope that is not the case. ------------- If you're going through hell, keep going http://www.correctcraftfan.com/diaries/details.asp?ID=2999" rel="nofollow - 89 Ski <a href="http://www.correctcraftfan.com/diaries/details.asp?ID=5685" ta |
Posted By: AndrewB
Date Posted: October-09-2013 at 12:29am
|
Sorry I typed wrong I had replaced both relays on the back not the ecm. I am just so skeptical about it being an exam because of the way the problem arises. I'm going to try a regulator. I may take the boat to someone after this. The cheapest I found an ecm for was 675. |
Posted By: AndrewB
Date Posted: October-09-2013 at 12:30am
|
I really need to make a friend with a known good ecm to rule it out. |
Posted By: wetskier2000
Date Posted: March-01-2020 at 11:16am
|
I see the first post says "solved" but I don't see the resolution in this thread..... What was the root cause? I have the same symptoms on a 1997 GT40. thanks ------------- Current: 1997 Nautique Previous: 1987 Nautique 1964 American Skier |