I bought this car from a buddy who said the fuel pump needed replacing. The fuse was fine, so I replaced the relay and the car started and ran fine. For three days it was good, then a couple of times it would start. On those occasions I pulled the relay, counted to ten, put it back in and it would start. Then finally, it died on me while driving and I had to get a tow home. The thing has sat in the driveway for a while, but with nothing else changing it starts and runs again.

What's your guess? Pump? Relay wiring? ECU? Some kind of short?

Thanks

If it's wired the same as a '93, the relay only supplies the "priming" +12volts fom the ECM for 2-3 seconds.

The Oil Pressure switch, which also operates the dash oil light, supplies the Fuel pump from the ignition switch and fuel pump fuse when the engine is running.

If you have, as in a '93, a fuel pump test connector in the engine bay you could use that to test for a 12volt supply to the pump.

It should show +12volts to Ground for 2-3 seconds when the ignition is switched ON and then +12volts when the engine is turning over fast enough to change over the oil pressure switch contacts.

You could also have an intermittant/bad connection in the relay base(socket) or an intermittant ground on the relay base(This could explain why the removal and refitting of the relay made it work before)

Hope some of it helps


Alont

"You could also have an intermittant/bad connection in the relay base(socket) or an intermittant ground on the relay base(This could explain why the removal and refitting of the relay made it work before)"

Exactly what I was thinking.




- 2004 Cavalier - 124k, owned since new

you mean the relay has to be bolted down to have ground?