Intermittent no start problem, help to identify?
Thread Starter
Le Mans Master
Joined: Jul 2000
Posts: 7,639
Likes: 326
From: Greenville SC
Yes, as I stated above "I installed a new high volume pump years ago, and a boost a pump, but only a few thousand miles on those. (maybe 10k tops)".
I did this myself about 13 years ago, also installed an Alky Control meth kit back then, but I don't think that could cause this issue. The problem only started doing this lately after working on lights and removing battery, it was difficult to start after reinstalling battery.
I always turn the key to run the pump first before starting. I just tried it 4 times, and I can hear the pump each time, but I also have fuel pressure, so I would expect to hear it. The FP (fuel pressure) did drop from 61 when parked yesterday, to about 54 now after turning key, but I think this is normal. When I had no FP the other day, I was not listening for the pump, just fixed on the FP gauge, so I don't remember if I could hear it or not. I was assuming the pump was not running since no FP, and why I tried the fuel pump fuse. I will have to remember to listen next time.
I did this myself about 13 years ago, also installed an Alky Control meth kit back then, but I don't think that could cause this issue. The problem only started doing this lately after working on lights and removing battery, it was difficult to start after reinstalling battery.
I always turn the key to run the pump first before starting. I just tried it 4 times, and I can hear the pump each time, but I also have fuel pressure, so I would expect to hear it. The FP (fuel pressure) did drop from 61 when parked yesterday, to about 54 now after turning key, but I think this is normal. When I had no FP the other day, I was not listening for the pump, just fixed on the FP gauge, so I don't remember if I could hear it or not. I was assuming the pump was not running since no FP, and why I tried the fuel pump fuse. I will have to remember to listen next time.
Melting Slicks
Joined: Sep 2008
Posts: 3,138
Likes: 802
From: Espanola New Mexico
Yes, you have to determine why sometimes you have no fuel pressure on start up. Is the fuel pump coming on, but not building pressure or is the fuel pump not turning on at all at start up. Several psi of pressure drop overnight is normal and nothing to be concerned with. Good luck in solving this as intermittent problems are a little harder to solve.
Thread Starter
Le Mans Master
Joined: Jul 2000
Posts: 7,639
Likes: 326
From: Greenville SC
I feel it may be an issue similar to this, as the symptoms are the same, and this all started happening after I upgraded headlights, removed battery, and some wires from the old lights to the ground at the battery base. Once I completed the install, the car would not start immediately after the install. Could be a coincidence, but it never happened before the install, so I think it is related. https://www.corvetteforum.com/forums...fuel-pump.html
Thread Starter
Le Mans Master
Joined: Jul 2000
Posts: 7,639
Likes: 326
From: Greenville SC
Tested it today on a short drive. (I have started it maybe 8 times over the last couple weeks, and always started.)
I drove through the neighborhood, stopped to talk to a neighbor, and after around 10 minutes at idle, and temp about 210, the car died.
No fuel pressure, and no fuel pump sound. Would not restart, giving it some time to retry.
I drove through the neighborhood, stopped to talk to a neighbor, and after around 10 minutes at idle, and temp about 210, the car died.
No fuel pressure, and no fuel pump sound. Would not restart, giving it some time to retry.
Tech Contributor
Joined: Jan 2007
Posts: 19,472
Likes: 1,171
From: Dyer, IN
Tested it today on a short drive. (I have started it maybe 8 times over the last couple weeks, and always started.)
I drove through the neighborhood, stopped to talk to a neighbor, and after around 10 minutes at idle, and temp about 210, the car died.
No fuel pressure, and no fuel pump sound. Would not restart, giving it some time to retry.
I drove through the neighborhood, stopped to talk to a neighbor, and after around 10 minutes at idle, and temp about 210, the car died.
No fuel pressure, and no fuel pump sound. Would not restart, giving it some time to retry.
Thread Starter
Le Mans Master
Joined: Jul 2000
Posts: 7,639
Likes: 326
From: Greenville SC
Well it wasn't practical to trouble shoot on the street. After trying many times over the last couple days, I decided to try once more today, and it started! I was amazed, as it had never been this hard to start, and I thought the pump was dead. It had showed 0 fuel pressure on the gauge when I tried it, but started up.
Now that it is in the garage again, I will trouble shoot when I have time.
A list of things to check, and in order would be appreciated?
I am going to apply 12v direct to the fuel pump to see if it starts.
Also, will check connector C130 around battery to see if it is damaged (see other thread I listed above where this was the issue) post #23
If nothing there, will look at the BAP, and Racetronix harness next.
Now that it is in the garage again, I will trouble shoot when I have time.
A list of things to check, and in order would be appreciated?
I am going to apply 12v direct to the fuel pump to see if it starts.
Also, will check connector C130 around battery to see if it is damaged (see other thread I listed above where this was the issue) post #23
If nothing there, will look at the BAP, and Racetronix harness next.
Tech Contributor
Joined: Jan 2007
Posts: 19,472
Likes: 1,171
From: Dyer, IN
Sorry, that does not make any sense. Either you have an issue with your method or gauge. They are hard starters with low fuel pressure, let alone NO fuel pressure. I do not believe you actually had 0 psi fuel pressure and the engine started and ran normally.
Thread Starter
Le Mans Master
Joined: Jul 2000
Posts: 7,639
Likes: 326
From: Greenville SC
Sure it does, I agree with you, it had to have pressure to start. I was just pointing out that the FP gauge on my A pillar showed 0, so did not think it would start, because nothing appeared different. On some of the recent attempts, the gauge did jump to 20, but would fall back after the next attempt.
The last time it didn't start, it took several attempts, and the FP increased each time, 20, 40, 60, then ran. It did increase to about 65 this time, not sure if that is indicative of a failing FP, higher than normal? It is holding there now, and will retain the pressure until I try to start it, and the FP doesn't run, and then will fall to 0 again.
The last time it didn't start, it took several attempts, and the FP increased each time, 20, 40, 60, then ran. It did increase to about 65 this time, not sure if that is indicative of a failing FP, higher than normal? It is holding there now, and will retain the pressure until I try to start it, and the FP doesn't run, and then will fall to 0 again.
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Tech Contributor
Joined: Jan 2007
Posts: 19,472
Likes: 1,171
From: Dyer, IN
Sure it does, I agree with you, it had to have pressure to start. I was just pointing out that the FP gauge on my A pillar showed 0, so did not think it would start, because nothing appeared different. On some of the recent attempts, the gauge did jump to 20, but would fall back after the next attempt.
The last time it didn't start, it took several attempts, and the FP increased each time, 20, 40, 60, then ran. It did increase to about 65 this time, not sure if that is indicative of a failing FP, higher than normal? It is holding there now, and will retain the pressure until I try to start it, and the FP doesn't run, and then will fall to 0 again.
The last time it didn't start, it took several attempts, and the FP increased each time, 20, 40, 60, then ran. It did increase to about 65 this time, not sure if that is indicative of a failing FP, higher than normal? It is holding there now, and will retain the pressure until I try to start it, and the FP doesn't run, and then will fall to 0 again.
Thread Starter
Le Mans Master
Joined: Jul 2000
Posts: 7,639
Likes: 326
From: Greenville SC
Well, I changed the pump and put my old LPE pump back in (was working fine when removed), and still no start. Same symptoms, I do not hear the FP turning on.
Fuel pressure on gauge did increase from 0 to 5, but nothing more. I really thought this was going to fix it.
The intermittent part (in the past, worsened over time, now for some time in a no start condition), makes it more confusing.
I guess the BAP box could have been failing, but think it is unlikely, and wouldn't it still pass current, the KB install guide says "The BAP is basically just a pass through much like an inline fuse." I believe mine just activates off the hobs switch when under boost. I looked at the in-line fuse to the BAP while I had the wheel off, and it was fine.
Fuel pressure on gauge did increase from 0 to 5, but nothing more. I really thought this was going to fix it.
The intermittent part (in the past, worsened over time, now for some time in a no start condition), makes it more confusing.
I guess the BAP box could have been failing, but think it is unlikely, and wouldn't it still pass current, the KB install guide says "The BAP is basically just a pass through much like an inline fuse." I believe mine just activates off the hobs switch when under boost. I looked at the in-line fuse to the BAP while I had the wheel off, and it was fine.
Moderator, Tech Contributor
Joined: Sep 2013
Posts: 15,626
Likes: 4,071
From: Cape Coral, Florida
You need to voltage drop the positive and negative side of your fuel pump from the battery to the pump…that’s all I can tell you…good luck and if you don’t understand this principle see a professional.
Thread Starter
Le Mans Master
Joined: Jul 2000
Posts: 7,639
Likes: 326
From: Greenville SC
I'm going to bypass the BAP and plug the OEM power connector into the pump like from the factory, and see if this works. If it works, I know it is the BAP or something in that line.
Thread Starter
Le Mans Master
Joined: Jul 2000
Posts: 7,639
Likes: 326
From: Greenville SC
You need to voltage drop the positive and negative side of your fuel pump from the battery to the pump…that’s all I can tell you…good luck and if you don’t understand this principle see a professional.
https://youtu.be/IuP0ZEHfDJ4?si=rYJSP2C7wXHj6mjz
https://youtu.be/IuP0ZEHfDJ4?si=rYJSP2C7wXHj6mjz
Thread Starter
Le Mans Master
Joined: Jul 2000
Posts: 7,639
Likes: 326
From: Greenville SC
Fixed. I plugged the OEM power connector back into the pump directly, bypassing the BAP.
Fuel pressure back to normal, 58 sitting not running, and 62 running, as least by the pillar gauge. I don't know why I didn't think of this much easier way to test the system, before removing the pump, I think I was certain it was the pump based on research, and more likely than an electronic solid state box.
Drove it and all is good. I don't see a reason to replace the BAP, does anyone else? Is there something not apparent that I am overlooking?
Fuel pressure back to normal, 58 sitting not running, and 62 running, as least by the pillar gauge. I don't know why I didn't think of this much easier way to test the system, before removing the pump, I think I was certain it was the pump based on research, and more likely than an electronic solid state box.
Drove it and all is good. I don't see a reason to replace the BAP, does anyone else? Is there something not apparent that I am overlooking?
Melting Slicks
Joined: Sep 2008
Posts: 3,138
Likes: 802
From: Espanola New Mexico
A BAP is usually installed when there is a need for an increase in fuel demand especially when you have a supercharger or turbos. My car with the A&A supercharger kit came with a BAP.
Tech Contributor
Joined: Jan 2007
Posts: 19,472
Likes: 1,171
From: Dyer, IN
Thread Starter
Le Mans Master
Joined: Jul 2000
Posts: 7,639
Likes: 326
From: Greenville SC
I installed it years ago with a bunch of other upgrades, including the Racetronix fuel pump, before having it retuned. I wanted to make sure there was enough fuel with the supercharger that was already installed, and not have to redo and take it back to be tuned again. I didn't have any issues before hand, but I didn't know what had been done, and I didn't know the PO had installed the Lingenfelter pump until later. This is why I don't think there is an issue, and it has good FP now, plus I don't push the thing racing etc.