Fuel problem

I have a 1992 Toyota pickup and the fuel pump

Is not coming on. I've changed the relay

Next to the glovebox and changed the fuel pump.

If I run a jumper from FP to the positive side of

The battery then I can here the fuel pump come on and the

Truck will run remove the wire and it dies. I don't know

What it could be. Any help would be appreciated thanks

Reply 1 : Fuel problem

IIRC the fuel pump is actuated by the MAF sensor in the top of the airbox.

Reply 2 : Fuel problem

Is there any way to test this?

Reply 3 : Fuel problem

When you jump the Fp and +B terminals you are bypassing the fuel pump interlocks, a switch in the MAF and the Circuit Opening Relay.



The switch in the AFM should show an open on an ohmmeter when the plate is fully closed and less than 1 ohm in any other position. That is measured between the Fc and E1 terminals of the AFM connector.



To check the COR, unplug it and check the following terminals with an ohmmeter:

STA to E1 - 17-25 ohms

+B to Fc - 88-132 ohms

+B to Fp - open

Reply 4 : Fuel problem

Thanks Fourwd1, I couldn't remember exactly how to test it.

Reply 5 : Fuel problem

Ok the checked it and it's good. What's next?