"88 won't accelerate

88 XJ Limited , 242, 4.0, 127K, auto, My XJ started to have a little "stagger" a month ago. Now, it will idle OK but will only go about 10mph. Pushing the gas it just has no power. Cat converter only has 26K on it and sometimes restarting it will have it run almost normal for a couple of minutes. Help!

try pushing the throttle linkage under the hood by hand and also check to see if the cable is not broken.

Ditto. If the throttle linkage is working normally and the throttle blade opens fully, I suggest you check the fuel pressure at the inector rail. A bad fuel pump is a distinct possibility.

The throttle position sensor would be my first suspect. Try discoing the wire harness connector and reconnecting it to get a better connection. Greg

Greg Smith said:

The throttle position sensor would be my first suspect.

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I don't think so. A bad TPS will cause bucking and hesitation but the engine will still have reasonable power, certainly enough to go a lot faster than 10mph!
If the fuel pump is still the original factory item from 1988, it's been living on borrowed time for a long time so that would be my first suspect. When the symptoms occur, remove the cover on the Schrader valve on the injector rail, put a cloth around it, and press the valve in while another person cranks the engine. The fuel should spurt out like a fountain. If it's only a mere trickle, the fuel pump's bad.

Thanks everyone. I checked the gas pedal linkage an it's not that. Sometimes it will run "normal" for a few minutes.