bdunlap77

ok i bought a 89 cherokee laredo with a 4.0 that had been sitting for 5 yrs with a bad fuel pump, i replaced the fuel pump and fuel filter, now it will start and automatically die, i thought maybe i should run a can of carb cleaner through it and still same thing, ive checked all the wiring harnesses to see if rats had chewed them and all that ive seen look fine, there are a couple of vaccum hoses that are chewed and i cant locate the other end. Any input would be greatfully appreciated.

cruiser54

There is a fuel pump ballast resistor located on teh driver's side inner fender. Your fuel pump gets power in the Start position and then runs the power through the resister in the On positon. Perhaps that's disconnected or has chewed wires?

bdunlap77

Everything there seems to be fine

cruiser54

Do this, and note the fuel pump relay location.

I suggest unplugging EVERY electrical connection in the engine bay you can find, whether engine related or not, and spraying it out with a good electronics cleaner, visually inspecting the terminals making sure they haven’t retracted into the plastic holder, and then plugging it back together. There’s a critical 10-pin connector for the front lighting system located in front of the air cleaner and behind the left headlight assembly. Don’t miss that one
. Also be sure that the connectors to the ballast resistor mounted near the air cleaner housing are clean and tight.

ALL of the relays should be removed, the terminals wire-brushed until shiny, and the receptacles sprayed out with contact cleaner. Then plug them back in. I do this on every Renix Jeep I purchase or work on for someone else.

Revised 07/23/2012

bdunlap77

Ok I have cleaned the wires, and put on a new cps, still not starting. Any other suggestions?

cruiser54

Bad ignition switch? Got a meter and know how to use it?

bdunlap77

Got one and kunda know how to use it

cruiser54

Did you pull all 4 relays and clean them up?

bdunlap77

Idk, I pulled every connection I could get to

cruiser54

Relays in post #4.

bdunlap77

Yes I pulled and cleaned all 4 of them

bdunlap77

There are still a couple of vacuum lines I haven't been able to trace down and they are not shown in the Chilton book

cruiser54

This help?

bdunlap77

That's the same diagram that's in the chiltens book but I couldn't find the lunes on that pic, thanks tho

cruiser54

I don't understand.