GT40 crank, no start, crank again and it fires
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=42358
Printed Date: May-03-2024 at 8:30am
Topic: GT40 crank, no start, crank again and it fires
Posted By: 2001Sunsport
Subject: GT40 crank, no start, crank again and it fires
Date Posted: January-30-2018 at 5:25pm
|
Trying to gather info before the boat comes out of storage. Found a number of threads with no start issues, but this boat always ends up starting. 1995 Supra Comp TS6M with the tubular intake GT40 and no FCC. Many times when attempting to start the boat, it will crank and not fire. Try a second time and it's about 50/50 on starting. Try a third and it always starts. Once started it will run great all day. Shut it off and same starting issue appears. Things to check from other threads: - Fuel rail pressure - every time I've checked was when the issue had already presented itself, and then it started on the next crank. No good data at this point, will have to check again during the first start attempt. - Replace relays - Check/clean electrical connectors on engine harness - Check ignition switch connections Any other thoughts? |
Replies:
Posted By: Dreaming
Date Posted: February-01-2018 at 9:02pm
|
Hi Andrew, it sounds to me like your Anti siphon valve might have a leak, or that you are getting air in your fuel system. I would try cleaning the antisiphon, checking to make sure that your tank vent is clear, and replacing the fuel filter. to me it sounds like your pumps are working, but it takes a couple of tries to fill the fuel rail. I may be totally off base, but they would be easy tune up items to eliminate before you dive into bigger and better things. Thanks for the post on Protec, Glad my old gear had a useful afterlife  it would be great to have an option for using TBI for anyone who hasn't replaced the system yet. |
Posted By: 2001Sunsport
Date Posted: February-01-2018 at 9:08pm
|
Thanks for the advice!! It took a while to get around to testing things out, but definitely wanted to share my findings. I probably would have been in more of a hurry if my Protec system had been failing.
|
Dreaming wrote:Posted By: 2001Sunsport
Date Posted: June-24-2018 at 11:15pm
|
Replaced both relays just because they were cheap. Didn't change anything, but figured I'd start there. Dreamings theory was pretty close. Put a fuel pressure gauge on the rail and turned the key to run, didn't move but heard both pumps. Tried again, 5psi, then 15, again, 30 once more and got 40. Ordered a low pressure pump from summit. Carter P4389, it's a marine pump. Old pump was a Carter 152-875. Pumps are identical on the outside. $55 plus the ride. Key on, first turn to run and rail pressure was 40psi! Think I found the issue. Low pressure pump was getting weak but could be coaxed into working. Thanks for the help! |
Posted By: Gary S
Date Posted: June-25-2018 at 1:19am
|
That's the pump,sure beats the 200+ the others want ------------- 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: June-25-2018 at 5:15am
|
Nice work! I have used a fuel pressure gauge with a 4 foot connecting hose to help diagnose fuel issues on fuel injected engines with intermittent issues. Hook it up and route the hose so you can run the engine and see the gauge. Makes it easy to seen what your pressure is in many situations. ------------- |
Posted By: Bri892001
Date Posted: June-25-2018 at 12:12pm
| Once you confirm that the LPP fixed everything, I 'll post this one up on the GT-40 diagnosis thread and spreadsheet. |
Posted By: wetskier2000
Date Posted: June-27-2018 at 11:50am
|
Which one is the low pressure pump on an FCC equipped GT-40? The one beside the FCC, external to the FCC? ------------- Current: 1997 Nautique Previous: 1987 Nautique 1964 American Skier |
Posted By: gun-driver
Date Posted: June-27-2018 at 12:16pm
|
This one https://www.summitracing.com/parts/crt-p4389" rel="nofollow - https://www.summitracing.com/parts/crt-p4389 |
Posted By: 2001Sunsport
Date Posted: June-27-2018 at 12:26pm
|
Just a heads up, I have a 1995 with no FCC. People more knowledgeable than I can confirm if FCC equipped boats use a different low pressure pump. Hopefully the weather will improve here and I can report back if the boat is 100% fixed shortly. |
Posted By: gun-driver
Date Posted: June-27-2018 at 12:29pm
They aren’t that knowledgeable then.  Same low pressure pump, different high pressure pump. https://www.skidim.com/Electrical/products/1057/" rel="nofollow - https://www.skidim.com/Electrical/products/1057/ |
Posted By: 2001Sunsport
Date Posted: July-09-2018 at 2:16pm
| No go on the LPP fixing the issue. Debating doing the HPP or waiting until the fall to pull the fuel tank. Can't get to the anti-siphon without pulling the tank on my Supra Comp. |
Posted By: 2001Sunsport
Date Posted: July-26-2018 at 12:53pm
|
So the latest symptoms are still the need to make the fuel pump prime 3-4 times before it starts, but also sometimes when launching a skier it feels like it falls on its face and other times it will rip their arms off. I'm leaning toward replacing the high pressure pump shortly, but wanted to ask if anyone thought a anti-siphon could cause the power differences in addition to the starting trouble. |
Posted By: gun-driver
Date Posted: July-26-2018 at 7:28pm
| Sounds like your high pressure is on its way out, if it was the anti siphon I would think it starve for fuel when full throttle also |
Posted By: 2001Sunsport
Date Posted: July-30-2018 at 2:50pm
| New high pressure pump showing up today...fingers crossed. I'll update with results. |
Posted By: gun-driver
Date Posted: July-30-2018 at 3:32pm
|
I’m guessing you went with this one, and are plugging the crossover line. https://www.summitracing.com/parts/crt-p61171" rel="nofollow - https://www.summitracing.com/parts/crt-p61171 |
Posted By: 2001Sunsport
Date Posted: July-31-2018 at 11:16am
Yes sir, and one of these adapters. https://www.summitracing.com/parts/fra-491956" rel="nofollow - https://www.summitracing.com/parts/fra-491956 Saw some older posts on here that said it seemed to work well. |
Posted By: 2001Sunsport
Date Posted: August-15-2018 at 1:58pm
| New high pressure pump seems to have solved the issue. Had one rough start after a hot soak, but boat has been running great and has all its power back. Gives a nice consistent pull every time now! |
Posted By: MrMcD
Date Posted: August-15-2018 at 2:28pm
|
Every once in a while, maybe once in 25 starts my factory stock GT40 will fail to start promptly. With these engines there should be no cranking, just turn the key and they fire. When mine does not fire immediately as it should I quickly turn the key to the off position then back to the run position and wait till I hear the fuel pumps pressurize before turning to start. Has worked each time for my boat. I think sometimes I rush to start before it has fuel pressure causing this condition. ------------- |
Posted By: Bri892001
Date Posted: August-15-2018 at 4:42pm
|
I'll log the high pressure pump as the fix in the GT-40 diagnostic thread. |