[Steve91T]

So yesterday when I started the car, it cranked but didn't fire. It did start on the 2nd try. Odd, I thought. So then on m way home, I was steady at 35 mph when, for about a second, the fire went out. I had nothing. Then it came back and all was well. So I was thinking that maybe the opti was having a bad day.

Fast forward to today and the car wouldn't start. Cranked, but wouldn't fire....didn't even try. I noticed I couldn't hear the fuel pump priming. I banged on the tank with a rubber dead blow and tried again. This time I heard the fuel pump prime and the car fired, but then quit. That was the last time I could get it to fire. I also noticed the fuel gauge is pegged full.

Soooo, time to cut an access above the tank?

[mr.beachcomber]

So yesterday when I started the car, it cranked but didn't fire. It did start on the 2nd try. Odd, I thought. So then on m way home, I was steady at 35 mph when, for about a second, the fire went out. I had nothing. Then it came back and all was well. So I was thinking that maybe the opti was having a bad day.

Fast forward to today and the car wouldn't start. Cranked, but wouldn't fire....didn't even try. I noticed I couldn't hear the fuel pump priming. I banged on the tank with a rubber dead blow and tried again. This time I heard the fuel pump prime and the car fired, but then quit. That was the last time I could get it to fire. I also noticed the fuel gauge is pegged full.

Soooo, time to cut an access above the tank?

Not sure how the fuel pump management is carried out on a Camaro; however, with the '89 Vette there is a fuel pump relay that closes momentarily to prime the fuel rails. Once the oil pressure reaches 4 psi during cranking, another signal is sent to the ECM to close the fuel pump relay for normal start/run. The situation you described happens to early C4's all the time when 1) either the fuel pump replay is bad or 2) the ECM signal to run the fuel pump is bad (no fuel pressure when running once the engine is running). I've had the later case happen to me, and like you described, the Vette loses power momentarily until the 'limp home" mode kicks in to fire the fuel pump to restore power.

If you have good fuel pressure at the fuel rails, it's probably not the in-tank fuel pump. It's probably a loose wire or bad relay causing the problem. (I once serviced a customer's Vette that had broken electrical connectors inside the male side of the fuel pump relay that caused an intermittent "no start" situation. Had to re-terminated all the Weather Pak connectors for the relay. (Turns out the customer replaced the relay by pulling on the wires themselves when separating the components.)

Hope this helps!

[trackbird]

Not sure how the fuel pump management is carried out on a Camaro; however, with the '89 Vette there is a fuel pump relay that closes momentarily to prime the fuel rails. Once the oil pressure reaches 4 psi during cranking, another signal is sent to the ECM to close the fuel pump relay for normal start/run. The situation you described happens to early C4's all the time when 1) either the fuel pump replay is bad or 2) the ECM signal to run the fuel pump is bad (no fuel pressure when running once the engine is running). I've had the later case happen to me, and like you described, the Vette loses power momentarily until the 'limp home" mode kicks in to fire the fuel pump to restore power.

If you have good fuel pressure at the fuel rails, it's probably not the in-tank fuel pump. It's probably a loose wire or bad relay causing the problem. (I once serviced a customer's Vette that had broken electrical connectors inside the male side of the fuel pump relay that caused an intermittent "no start" situation. Had to re-terminated all the Weather Pak connectors for the relay. (Turns out the customer replaced the relay by pulling on the wires themselves when separating the components.)

Hope this helps!

I was just coming in here to add that information. However, I believe the oil pressure switch (for the fuel pump) is redundant (parallel) in the Camaro. Turn the key, the pump primes, start cranking and the fuel pump relay closes. If the relay is bad, when the car sees a few PSI (4-5?) of oil pressure, the oil pressure switch closes and turns on the fuel pump anyway. So, you tend to see extended cranking times, but the car will typically start if you crank long enough.