4 Wheel Drive/SUVs: 99 jeep cherokee sport, jeep grand cherokee, jeep cherokee sport

Question
When the car is idling it seems to almost jump forward at times and died once.  Also when driving at any time it seems as if the car hiccups or knocks or jumps (whatever term.  One time it also would not die when I turned the key off and later when I turned the ignition on it seemed to partially start.  After 2 or three times it started correctly.  It doesn't do this all the time.  I have had it to 3 separate mechanics who cannot find anything wrong.  I'm annoyed.

Answer
This seems to be a common problem in jeeps but I  pulled this Q/A from the car doctor.com and it quotes:

Q. I have a 1996 Jeep Grand Cherokee, and for the past 8,000 miles the coolant light has been coming on. Although the dealer has tried to fix the problem a second issue has started: The check engine light comes on and the Jeep bucks. Recently the crank shaft sensor was replaced but the Jeep still bucks for the first five minutes of driving. The mechanic is stumped; do you have any ideas?

A. Your repair shop needs to start with diagnosing the "check engine" light. This light is indicating a failure of one or more of the computer sensors. The two common issues are faulty oxygen sensors and a faulty crankshaft position sensor. Although this was replaced once, in this case I would suggest only a factory part.


Maybe try one of these and see if it helps

Matt