Fuel prime question, not a normal application.

[snookwheel]

Hi folks, I have followed this forum for quote a while to learn all I can about the 3.8 SC engine. But now, in spite of searching with reckless abandon, am stumped. I have a 3.8 SC out of a 2002 Grand Prix, it really has been a maintenance free power plant. It installed in a Brunton Super Stalker, a version of a lotus Super 7.

I was out for a ride last weekend and the engine cut off, it would crank but not restart. I got the Tow-of-shame home on a flat bed and started poking around. The fuel pump relay had gone bad, but now the car does not prime when I turn on the key. I can jump the relay to make the pump run when starting, after it starts, I can remove the jump and the pump continues to run and all is good. I've checked and do have power running to the 'start/run' wire, just no pump running.

Putting in a bypass switch to use when starting the car works fine, I shut that switch off after starting and the pump does its thing. Any ideas why I seem to have lost the Start/run circuit? I've checked all the fuses... At a loss.

Thanks for taking time to read my saga, Scott

[lewis1952]

Did you re-learn the fuel pump when you got everything hooked up and running? Try this, turn the key on but don't try to start it. Wait 2 seconds then turn it off for 10 seconds. Then on for 2 and off for 10, Then try starting it. Sounds like the ECM isn't recognizing that you have turned the switch on and therefore isn't sending the message to the fuel pump to begin priming.

[snookwheel]

I just tried it, nada. It is easy to hear the pump run, when it runs. I used to hear it as soon as I turned the key, now nothing. But thanks for giving it a shot.

[Fivefingerdeathpunch]

Maybe the fuel pump resistor in the wiring is bad too.

[snookwheel]

I'm pretty sure the resistor has been deleted, it has a Wilbro fuel pump. The mystery is why the start fuel pump circuit has died. I checked and there is power to the lead when the switch is turned on. Possible computer issue?