C5 manual corvette starts then immediately stalls after 1-2 seconds

[Rruuff Day]

Well now you've got a place to start at least. Hopefully you cure it first shot.

 

[Hunter]

Update: I got a fuel pressure gauge and I have a whole 11 psi which is what they call bad. So it sounds like a fuel pump with 57k miles on it has gone bad but then again it’s an 18 year old pump. I’ll be taking the fuel system out and replacing as much as I can. I’ll keep you guys updated. Thank you for all the help

 

[ddgermann]

Well that’s unfortunate to discover Valerian. But at least you know the problem now. There will be many followers on this thread as it’s a job that doesn’t get done very often. Your photos and descriptions will help the gang out tremendously.

 

[theboss]

I dont know if you can reach the connector for the fuel pump without removing it but if you can check on the left fuel thank there is a gray wire (12V) to feed the fuel pump and a black for the ground, I normaly connect a sealed beam or something that will use 8 amps or more to check the strength of the circuit and relay. I would also try a fuel filter first, way cheaper and a smaller job to.

Good luck and keep posting

Stephane

 

[Nik]

Update: I got a fuel pressure gauge and I have a whole 11 psi which is what they call bad. So it sounds like a fuel pump with 57k miles on it has gone bad but then again it’s an 18 year old pump. I’ll be taking the fuel system out and replacing as much as I can. I’ll keep you guys updated. Thank you for all the help

I'm shocked it even started with that little pressure. Good luck, you've narrowed the issue. Good time to replace the pump with a higher output unit. Racetronix used to do plenty of fueling solutions.

 

[LE BARON]

I dont know if you can reach the connector for the fuel pump without removing it but if you can check on the left fuel thank there is a gray wire (12V) to feed the fuel pump and a black for the ground, I normaly connect a sealed beam or something that will use 8 amps or more to check the strength of the circuit and relay. I would also try a fuel filter first, way cheaper and a smaller job to.

Good luck and keep posting

Stephane

Great advice!
KISS - Keep it Simple Stupid! You eliminate the easy stuff before diving in deeper - only to find out it was the easy stuff to begin with.
Once rebuilt a diesel fuel pump. The customer bought new fuel filter for it. He came back with the bulldozer a few days later with low power complaint. It would start well but once it started to push some dirt it lacked power. The problem ended up that he had incorrectly installed the fuel filter and the O'Ring was partially blocking the flow. Luckily that was where we started to trouble shoot - right at the beginning - even though he had purchased a new filter. So don't skip any steps. Before you change the light switch make sure there is power to it - at the correct v/amps

 

[Hunter]

Ok so it’s been a while and I’ve gotten nowhere. The fuel pump is working and the filter is changed. It still reads 12psi. I can crank the car and get it to rev if I lightly tap on the gas but immediately when I stop the car sputters and dies. I’ve gone through and checked the ground to make sure they weren’t corroded which they weren’t because it’s a 50k Mile car. I’m not really sure where to go from here

 

[ddgermann]

So does the run at a steady RPM with your foot into the throttle? If so... what RPM does it run at? Or do you need to keep moving on and off the throttle to keep it from over reving?

 

[theboss]

12 psi is way to low. My next test would be to feed the fuel pump with jumper wires direct from the battery, if preasure is still low then you will probably have to lower the fuel tank. I am curently on the road so no acces to my shop my links to information otherwiae I woul of tell you what color for the wires. last think that cross my mind, if the car have a fuel return line, it will also have a fuel preasure regulator. If you dont find the infos and if you can wait until Monday, I will check and get back to you on Monday.

Good luck.
Stephane.

 

[Nik]

Ok so it’s been a while and I’ve gotten nowhere. The fuel pump is working and the filter is changed. It still reads 12psi. I can crank the car and get it to rev if I lightly tap on the gas but immediately when I stop the car sputters and dies. I’ve gone through and checked the ground to make sure they weren’t corroded which they weren’t because it’s a 50k Mile car. I’m not really sure where to go from here

I can't remember off top of head if fuel pressure regulator was on the fuel rail, on the fuel tank or part of the filter assembly. If it's a separate piece, go ahead and replace that. Next I would check voltage to the fuel pump, low voltage situation could potentially do something similar. Do you run a boost a pump or some other overvolt device? Bypass it if that's the case. There could be other restrictions in the system that you need to isolate (crimped lines, schrader valve issues etc).

 

[Hunter]

So does the run at a steady RPM with your foot into the throttle? If so... what RPM does it run at? Or do you need to keep moving on and off the throttle to keep it from over reving?

It won’t run at a steady rpm. If I let it sit after turning it on with sputter out. If I tap the gas I can get it to jump rpms a bit and if I keep tapping the gas lightly the rpm will keep jumping although it doesn’t seem to go above 5k rpms. Immediately after I let off the gas pedal or I give it too much it sputters out

 

[Hunter]

So does the run at a steady RPM with your foot into the throttle? If so... what RPM does it run at? Or do you need to keep moving on and off the throttle to keep it from over reving?

12 psi is way to low. My next test would be to feed the fuel pump with jumper wires direct from the battery, if preasure is still low then you will probably have to lower the fuel tank. I am curently on the road so no acces to my shop my links to information otherwiae I woul of tell you what color for the wires. last think that cross my mind, if the car have a fuel return line, it will also have a fuel preasure regulator. If you dont find the infos and if you can wait until Monday, I will check and get back to you on Monday.

Good luck.
Stephane.

I will check that thank you

 

[Hunter]

So does the run at a steady RPM with your foot into the throttle? If so... what RPM does it run at? Or do you need to keep moving on and off the throttle to keep it from over reving?

12 psi is way to low. My next test would be to feed the fuel pump with jumper wires direct from the battery, if preasure is still low then you will probably have to lower the fuel tank. I am curently on the road so no acces to my shop my links to information otherwiae I woul of tell you what color for the wires. last think that cross my mind, if the car have a fuel return line, it will also have a fuel preasure regulator. If you dont find the infos and if you can wait until Monday, I will check and get back to you on Monday.

Good luck.
Stephane.

Ok so it’s been a while and I’ve gotten nowhere. The fuel pump is working and the filter is changed. It still reads 12psi. I can crank the car and get it to rev if I lightly tap on the gas but immediately when I stop the car sputters and dies. I’ve gone through and checked the ground to make sure they weren’t corroded which they weren’t because it’s a 50k Mile car. I’m not really sure where to go from here

I can't remember off top of head if fuel pressure regulator was on the fuel rail, on the fuel tank or part of the filter assembly. If it's a separate piece, go ahead and replace that. Next I would check voltage to the fuel pump, low voltage situation could potentially do something similar. Do you run a boost a pump or some other overvolt device? Bypass it if that's the case. There could be other restrictions in the system that you need to isolate (crimped lines, schrader valve issues etc).

The fuel pressure regulator is in the fuel filter. Which I changed out. I’m checking now for any inconsistencies in the lies and seeing if I can hook up the fuel pressure gauge in various places to check what’s going on

 

[2001z06]

Having this same issue with my 2001, did you ever resolve this??

 

[Rruuff Day]

Having this same issue with my 2001, did you ever resolve this??

Welcome to the forum 2001 Z06. We haven't heard back from Valerian on this issue. You might get a response if you private message him. Hover over his avatar at his post and click where is says "start conversation" bottom right... Also might want to post the question in a new thread in this section of the forum.. Good luck.

 

[Timj7651]

Sorry about not introducing myself. Not familiar with this site just yet.

Update: I went and got a new battery - didn’t work
I checked the bcm and ecm and they are fine
My ignition switch is working fine and if I remember correctly cats are the security system which I believe I’m not having trouble with since there are no lights up.

Some backstory before this goes any further: About two months ago my slave cylinder went out and I had a minor ticking in the engine due to the previous owner of my c5 not keeping up with her. So I broke the car down and replaced push rods, lifters, clutch/flywheel, new swaybar links and bushings, a lowering kit, and I cleaned the pistons because the amount of buildup was horrid. I have everything back together now and whenever I go start it the car will run for 2 seconds and then it kills itself like something is shutting it off. I’m absolutely stumped on this and I’m not sure where to go from here.

 

[mdegen93]

After some fiddling around I’ve managed to keep it alive by barely tapping the gas when it’s about to cut off then I’m able to get another 2 seconds out of it so now I’m really thinking it’s the fuel pump

Could be the pcv valve stuck open causing the car to lean out

 

[Hunter]

Been a while and I had forgotten about this thread and I feel I should bring it to a close. I have since gotten the car to run it turns out one of the grounds for the fuel pump wasn't making a good connection. The car definitely gave me the run around for such a small issue luckily I didn’t blindly buy parts trying to fix things that weren’t broke. Thank you for everyone who helped me get to my solution. I hope this can help someone in the future.

 

[Black 03 Z06]

Thanks for bringing your tech issue to a conclusion. So often the members offer advice but the thread itself is never really closed with a cause/solution.

Glad you got it running and appreciate you coming back to us. Good tip for anyone with a C5 would be to clean and tighten all ground points, these cars just seem susceptible to these electrical issues.

@Hunter wonderful you got the beast running.