92rs85berlintta

iTrader: (1)

I keep running into a random problem with my lt1swap

It runs great most the time but periodically it wont turn on the fuel pump.
If I jump the relay with a wire the car will run and drive.

My computer isn't telling my fuel pump to turn on.

What would cause the computer to tell it NOT to prime or give fuel?

Bad oil switch?

I notice there is two, one for the gauge on the back of the motor and one at the pan for some reason.

Any ideas?

Thanks!

vetteoz

iTrader: (13)

To make it work or to bypass it ?

Depending how you wired your pump for the swap ,stock there was a oil pressure switch that runs the pump independent of the pump relay as soon as you crank the engine over .
This allows you to start the engine if the relay fails ( you don't say if you have tested the relay ????? )

The sensor in the pan is for oil level.
Depending whether you swapped over the 3rd Gen sensors or used LT1 ones you should have a 3 wire unit that is a combined oil gauge sender and the pump OP switch

92rs85berlintta

iTrader: (1)

I have the stock thirdgen relay and there is a hot wire that runs from the cpu to the relay that feeds it.

If I pull the relay and run a hot wire from the constant relay hot wire then the pump will run and the car will run. my upper oil pressure switch is single wire lt1 style, my lower oil switch I believe is two wires.

vetteoz

iTrader: (13)

That bypasses the relay completely;
what you need to do is test the relay to see if it actually works

With the relay in place you need to put 12V on the green /white wire terminal the same way the ECM does when it turns the relay on. You can jumper 12V from the org wire in the relay connector that is hot . 1st confirm that the black wire is to ground or the relay won't work

The relay should click and the pump run. If it doesn't then the relay is suspect