My '96 Cherokee is acting strange It was losing a lot of power climbing hills or accelerating. I did a fuel pump check and replaced the pump. The problem seemed to be solved until I drove it about 50 miles. The speedodmeter has been jumping for quite some time above 40, However it only does it after it's been driven for an hour or so. The Jeep will not stall and has plenty of power and no backfires until the speedodoemeter starts bouncing. When this happens you can accelerate and she'll just pop and buck until you back off the pedal. What connection would the speedodometer have to such an erratic behavior. Again, it;s only after it has been driven for an hour.
Thanks,
Don

 

The PCM relies on a vehicle speed sensor to handle transmission and fuel adjustments, replace the speed sensor and inspect the gear on it for any broken teeth.

 

Sounds resonable, I'm going out to pull it now.
Thanks

 

Yep, that fixed it. I would have never believed the speed sensor could couse that much of a problem.
Thanks,
Don