Okay I have a 88 Pickup 22RE. I'm having a fuel pump issue. I have taken the pump out & hooked it straight to a battery & it works. But when I drop it in the tank an plug it back up it doesn't work. I have check all fuses under hood an under dash! & still nothing. What else could possibly be wrong!

1986 Reg Cab 5speed 22r 3" lift on 35x15.5 Super Swampers!

 

try hooking up a multimeter to the fuel pump and see if you are geting any power

 

No power to the pump

1986 Reg Cab 5speed 22r 3" lift on 35x15.5 Super Swampers 1988 Ext Cab 22RE 5 speed

 

well being it is electric have you checked anything??

EFI fuse working like it should??

EFI Relay??

Circuit opening Relay?/

Then don`t forget the switch in the AFM

Could just be a bad ground.

Could be damaged wiring some place.

Like all electrical problems start at the power source and trace to the load

 

I've check every fuse on this thing. Every one looks fine.

1986 Reg Cab 5speed 22r 3" lift on 35x15.5 Super Swampers 1988 Ext Cab 22RE 5 speed

 

The power to the fuel pump should be a yellow/red. At least it is in an 86. In the circuit there is a switch in the AFM (air fuel meter), a circuit opening relay and various connectors that could be the problem. You need to work from the fuel pump back to the source to find the problem. Where you have had the fuel pump out you can verify the power wire colour. There is a connector under the passengers seat that connects the body, harness to the cab harness, disconnect it and check for 12volts to ground on the yellow/red of the cab harness side with the key on. If 12v. Then the problem is between there and the fuel pump. If not then go to the circuit opening relay behind the passengers speaker and check the yellow/red there. If not 12v then go to the AFM, etc.

 

You can also jumper two connectors in the diagnostic connector under the hood to put battery direct to pump. Batt+ and FP terminals on the connector. Just use a paper clip.


If it runs when you do that you know the wiring back to the pump is good and you need to check the AFM or COR.


Get a wiring diagram.

 

You have everything in this thread to fix your problem. I highly doubt looking at fuses and a general check is going to do anything for you...