Fuel Delivery Issues
Thread Starter
Racer
Joined: Jul 2008
Posts: 437
Likes: 3
From: Indiana
Fuel Delivery Issues
Hi guys, 99 C5 with fuel issues. I turned the car off and it wouldn't restart, pump was not priming, car would turn over but not fire. I pulled the harness out of the pump and checked voltage and found 12V when turning the key to the on position but would go to 0V after about 2 seconds, no priming sound from pump. I got in the car and turned the key immediately to the start position and car fired up, prior I was letting it sit in the "on" position for a few seconds before starting. Took car to garage and parked it for a couple hours, then went back to check on it and the fuel pump was priming and car fired right up. Drove the car for 30-45 mins then parked it and car again wouldn't start. Waited a couple hours and it fired right up.
I'll be looking into it further but wanted to see if anyone has experienced anything like this before. Car will start fine after sitting for a while (1-2 hours) but not after driving.
Pump is about 3 years old Racetronix with a few hundred miles on it.
I'll be looking into it further but wanted to see if anyone has experienced anything like this before. Car will start fine after sitting for a while (1-2 hours) but not after driving.
Pump is about 3 years old Racetronix with a few hundred miles on it.
Acct Suspended APR 2026 by request
Joined: Dec 2010
Posts: 10,367
Likes: 1,272
2020 Corvette of the Year Finalist (performance mods)
C5 of Year Winner (performance mods) 2019
remove the fuel pump relay in the under hood fuse box and jump the 30/87 terminals and see what happens... do this when the car is hot and won't start, when jumped it should run full time until you remove the jumper wire... if this works then it's possible the relay is bad or has a bad connection to the fuse box, the pins in the fuse box love to spread apart
Last edited by StingrayRebel; May 23, 2021 at 01:17 AM.
Moderator, Tech Contributor
Joined: Sep 2013
Posts: 15,628
Likes: 4,074
From: Cape Coral, Florida
Hi guys, 99 C5 with fuel issues. I turned the car off and it wouldn't restart, pump was not priming, car would turn over but not fire. I pulled the harness out of the pump and checked voltage and found 12V when turning the key to the on position but would go to 0V after about 2 seconds, no priming sound from pump. I got in the car and turned the key immediately to the start position and car fired up, prior I was letting it sit in the "on" position for a few seconds before starting. Took car to garage and parked it for a couple hours, then went back to check on it and the fuel pump was priming and car fired right up. Drove the car for 30-45 mins then parked it and car again wouldn't start. Waited a couple hours and it fired right up.
I'll be looking into it further but wanted to see if anyone has experienced anything like this before. Car will start fine after sitting for a while (1-2 hours) but not after driving.
Pump is about 3 years old Racetronix with a few hundred miles on it.
I'll be looking into it further but wanted to see if anyone has experienced anything like this before. Car will start fine after sitting for a while (1-2 hours) but not after driving.
Pump is about 3 years old Racetronix with a few hundred miles on it.
Last edited by C5 Diag; May 23, 2021 at 03:17 AM.
