New here just picked up an '88...have a few questions

Well as the title says I just got an '88 Cherokee Pioneer, 4door, 4x4, 4.0l, auto for $800. Its fairly clean, even the a/c and radio still work and it ran good on the test drive/way home. Im guessing it needs a fuel pump now. Its getting power to the pump but I really cant hear it kicking on and no pressure at the port on the fuel rail. It will crank for a few seconds, fire up, then die right away, giving it throttle doesnt help a bit. Any tips or advise on replacing the pump? I've done the job on my Silverado twice within the last year, just wondering about these XJ's. Another thing is the throttle sometimes sticks when I go WOT. I took the whole thing apart, well the bracket that the cables run through up under the hood, with the lever thing that rotates (know what i'm talking about). It sticks when it turn it all the way open or all the way closed. Should it be able to spin freely all the way to the stop or is it supposed to stick before it gets there? I hope someone has had this problem before. Sorry for the long first post, i'm just trying to get this thing roadworthy and get it fully tuned up and fluids changed etc...before i start ordering fun parts

I had a 1990 Cherokee that did the same thing. It would start right up and stall, whether or not you gave it gas. After changing the fuel pump, fuel rail, and injectors, we replaced a stupid little balist resistor that was 7 dollars, and that fixed the problem. Apparently that resistor controls the fuel flow, and wasnt allowing enough pressure to build up. I'd say try that seeing how its a cheap part, it bolts in right above the factory airbox, not sure about the '88 though.

I just bought an '88 two weeks ago also. Had the same problem.

There is a port on the fuel rail that should hold pressure when shut off. I found that there was no pressure when the engine was shut off. After pulling the fuel pump from the tank to replace it I found the hose from the pump to the fitting inside the tank was totally rotted. Not enough fuel to keep the XJ running. After replacing the pump and hose it ran fine.

You can get to the assembly from under the truck but it is tight. If you can drop the tank it may be easier.

Good luck.

Yeah check the ballast resistor on the drivers near the airbox. It's a white rectangluar thing with a wire coming out each end. It can be jumpered and removed if it's damaged.

Welcome to the world of Jeeps. I have an '88 Laredo.

You should have (at least) 31 PSI of fuel pressure at the test port with the key on. Get a pressure gauge to make sure. When it's running, disconnecting the vacuum line on it should show a pressure 0f 39 PSI.

If you truly have no pressure at the rail with the key on (running or not), then check the ballast resistor as Bison and Lawson say. You can simply connect the 2 wires and bypass it to test. You should hear the fuel pump whine when you turn the key to RUN.

The linkage should not stick. It should move freely over the whole range from closed to WOT. You might need to disconnect all of the cables (one at a time) to see which one is binding.

Saudade said:

The linkage should not stick. It should move freely over the whole range from closed to WOT. You might need to disconnect all of the cables (one at a time) to see which one is binding.

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Thanks all, i'm going to try the ballast resistor and check the fuel pump relay this weekend, apparently there are 2 relays running the pump?


The cables are all free from closed to WOT, the thing on that bracket that rotates that a cable and that strange arm mechanism attatches to sticks when at WOT and when I pulled it out of the car it would stick all the way closed and all the way open. I'm sure thats whats causing the binding, the throttle opens and closes manually just fine and all the cables are free to move....anyone seen this before?