1995, start, cough, die problem solved |
Post Reply |
Author | |||
1xsculler
Senior Member Joined: July-02-2016 Location: Gig Harbor, WA Status: Offline Points: 130 |
Post Options
Thanks(0)
Posted: August-04-2018 at 10:24pm |
||
With the help of Gun-Driver I am optimistic that I have solved the extremely frustrating, intermittent, start, cough and die syndrome that plagued non-fuel cell 1995 GT40s. Gun-driver sent me a Carter high pressure fuel pump without the return to tank fitting which I fitted along with a new low pressure pump I was going to install on my 1994 SN last season and I replaced the Fram 3780 fuel filter. My engine has run perfectly all day today with zero starting problems so I am keeping my fingers crossed that all is good to go. On final analysis I think my fuel filter may have been the problem all along as it seemed to be almost totally plugged whereas the new one was very free flowing to my blowing through it. I am going to go out and try to start it now as it has sat for about 45 minutes with the dog house down which was a situation that was a problem previously. |
|||
1xsculler
Senior Member Joined: July-02-2016 Location: Gig Harbor, WA Status: Offline Points: 130 |
Post Options
Thanks(0)
|
||
Yup, good to go, problem solved I'm 99% sure.
If you want to conquer this problem and you don't want to drop $800 for an aftermarket fuel cell kit: Buy a Summit Racing Marine, black, in-line high pressure fuel pump and find a flare fitting for the single bottom inlet to mate with the fitting from the low pressure pump also available from Summit Racing, I expect. They probably have a good match for the fuel filter too. Install all of this stuff and plug the fuel return to tank from the original HPP. This an easy DIY project and it may allow you to return to a sane state if you were frustrated by this problem. |
|||
MrMcD
Grand Poobah Joined: January-28-2014 Location: Folsom, CA Status: Offline Points: 3602 |
Post Options
Thanks(0)
|
||
I have been a fan of the repair you did for a couple years now. Way to go, that is how I would have fixed the HPP.
What was your solution to the return line that formerly plugged into the HPP. Any pictures? Glad you got it fixed. |
|||
gun-driver
Grand Poobah Joined: July-18-2008 Location: Pittsburgh, Pa Status: Offline Points: 4112 |
Post Options
Thanks(0)
|
||
Eliminate it. 5/8 x 18 -6 fitting needed for mating HPP to LPP https://www.summitracing.com/parts/fra-491956/overview/ |
|||
1xsculler
Senior Member Joined: July-02-2016 Location: Gig Harbor, WA Status: Offline Points: 130 |
Post Options
Thanks(0)
|
||
Yup, just eliminated it. Any number of ways fro.m a simple plug to taking it out and connecting the open ends.
|
|||
1xsculler
Senior Member Joined: July-02-2016 Location: Gig Harbor, WA Status: Offline Points: 130 |
Post Options
Thanks(0)
|
||
well, it did start, cough and die once when I tried to start it to flush it out but on the second try it started right up so I remain fairly confident that I am good to go. To finish the answer about the fuel return from the base of the HPP; Evidently it is not necessary at all. The fuel return from the fuel rail is still connected to the tank. I just eliminated the "T"and went directly to the tank. It would have been easier to plug the end of the stainless steel braided line which exited the base of the pump with the appropriate plug. |
|||
gun-driver
Grand Poobah Joined: July-18-2008 Location: Pittsburgh, Pa Status: Offline Points: 4112 |
Post Options
Thanks(0)
|
||
My guess would be air in the line from changing pumps and filter |
|||
tryathlete
Platinum Member Joined: April-19-2013 Location: Lake Villa, IL Status: Offline Points: 1797 |
Post Options
Thanks(0)
|
||
Even with the FCC, I had to bleed the air out after filter change which surprised me. I had the typical failing LPP issue when I bought my 96. On my third season with zero issues and that’s a charm!
|
|||
1xsculler
Senior Member Joined: July-02-2016 Location: Gig Harbor, WA Status: Offline Points: 130 |
Post Options
Thanks(0)
|
||
I will bleed the fuel rail next time I go out and I think I will "prime" the pumps several times by turning the key on for the few seconds the pumps run immediately after turning the key on. The anti siphon valve and the fuel pressure regulator are about the only components I have not changed out.
I hope to get some more run time today and I remain optimistic that the start, cough and die frequency is reduced to a point where my wife will trust our boat enough to enjoy it with our family.. I always did trust it but had to finally admit that it was frustrating when the start, cough and die issue seemed, on rare occasion, to be getting worse. |
|||
Hagan
Newbie Joined: August-13-2017 Location: Albany, OR Status: Offline Points: 17 |
Post Options
Thanks(0)
|
||
I thought the pumps ran for ~3 seconds when you turn the key on? That's how the automotive applications work at least. Cant imagine they changed that in a marine application.
There shouldn't be any bleeding involved the air will work itself out. |
|||
gun-driver
Grand Poobah Joined: July-18-2008 Location: Pittsburgh, Pa Status: Offline Points: 4112 |
Post Options
Thanks(0)
|
||
Yes they do run for a couple seconds when you first turn the key to on to charge the line with the right amount of pressure. That’s one of the things you should always listen for allowing them to charge the line before turning the key to start. But in his case he had opened the line to change the both pumps and filter so it only had the fuel in the line above the HPP which allowed it to start then die until the pumps were able to purge the air out of the line. Yes cycling the pumps a couple of times would have helped purge the air but we don’t know if he did that. The proper way would have been to hook up a pressure gauge with a release valve then jump the pumps so they run continuously and allow the air to escape out through the schrader valve. Bottom line is he’s up and running again. And yes there should be no reason to bleed the line now once you had it running. |
|||
Bri892001
Grand Poobah Joined: September-27-2008 Location: Boston MA Status: Offline Points: 4945 |
Post Options
Thanks(0)
|
||
I'll add this one to the GT-40 diagnosis thread.
Basic summary being "pre-FCC high pressure fuel pump replaced with Carter fuel pump, and fuel return line elimination." Does that sound about right? |
|||
1xsculler
Senior Member Joined: July-02-2016 Location: Gig Harbor, WA Status: Offline Points: 130 |
Post Options
Thanks(0)
|
||
To re-clarify my situation:
My 1995, pre fuel cell, multiport, fuel injected GT40 would intemittantly start, cough and die. It didn't really bother me all that much because I trusted that it would only happen rarely and it ran and started perfectly except for the few times when it wouldn't. It drove my wife nuts to the point where she no longer wanted to take the boat out. So, with consultation and a fuel pump from gun-driver I replaced the fuel filter, which was clogged to the point where I could just barely blow air through it (the new one was very, very easy to blow through), replaced the low pressure pump with a new automotive,but otherwise identical to the original which I was going to install on my '94 SN but never did and replaced the HPP with the one I got from gun-driver which appeared to be identical to the original pump except it has no third port to take excess fuel back to the tank. I eliminated that fuel return. There is still a fuel return from the fuel pressure regulator to the tank. The engine started right up and ran and started with no problems all day yesterday until after it was tied to the dock for an hour and then I had one episode of start, cough and die but it started on the second and future attempts. I am fairly confident that I am good to go for the rest of the summer, BUT, time will tell. Sorry for the repetitiveness and I thank all on this forum, especially gun-driver, for weighing in on this issue. I hope this will help others solve this problem that seems to plague only 1995s.. |
|||
MrMcD
Grand Poobah Joined: January-28-2014 Location: Folsom, CA Status: Offline Points: 3602 |
Post Options
Thanks(0)
|
||
I would T into the line between the Low pressure pump and the HPP. Hook the return line back in as it was from the factory.
The HPP can't run dry, In 10 seconds dry run time the HPP will self destruct. The motor is fuel lubricated and if dry the bushings start to gaul. Once that happens the pump will start to get noisy then get louder and then fail. In a noisy boat you may not hear this sequence. My only idea so far as to the existence of the HPP second return line to the inlet of the HPP is to help avoid the dry start failure. The low pressure pump will suck fuel from the tank and can run dry for a bit without damage. Since this pump is not in tank there is a time delay between power on and fuel reaching the HPP. The HPP needs fuel right away when power hits. I may very well be all wet on this thought but it is the only reason I have come up with for the existence of the 2nd return line feeding the HPP. All modern fuel injected cars use an in tank pump to avoid dry starts with the High Pressure pump. Our boats do not use an in tank pump so the FCC or the original 2 pump design are necessary. |
|||
gun-driver
Grand Poobah Joined: July-18-2008 Location: Pittsburgh, Pa Status: Offline Points: 4112 |
Post Options
Thanks(0)
|
||
I'm not buying this one, I can't believe an auto/marine manufacturer or Carter would install/make a fuel pump system that the first time you run out of gas the fuel pump is junk When I was testing theories last year with the pumps out of my boat trying to replicate the cause, I ran my pump dry quite a few times trying to heat it up but it still pumped and I didn't notice any difference in noise or volume being pumped. If the crossover line was a return to the pump wouldn't it draw against the return regulator during wide open throttle when the engine vacuum is trying to keep it closed? When I dissected my old pump there is a little red flapper/diaphragm valve in the bottom of the pump with ports to the extra line that seemed to be an out valve not in??? |
|||
Post Reply | |
Tweet
|
Forum Jump | Forum Permissions You cannot post new topics in this forum You cannot reply to topics in this forum You cannot delete your posts in this forum You cannot edit your posts in this forum You cannot create polls in this forum You cannot vote in polls in this forum |