My 1995 jeep has begun to buck, sort of like a miss above 45. My wife said it occured above 65 for her and said the tach went to zero then came back. It has occurred once for me and 5 times for her on a 200+ mile drive she was on today. It idles fine. Any ideas?

 

I had the same problem in my '00. It got much worse after a week and I wound up stalling on the highway doing 75 at one point. It seemed to happend whenever it felt like it and it would stall anywhere from 15 - 75 mph. It would up being the crankshaft positioning sensor. Are you stalling at all also?

 

when dose it happen over bumps or when its wet? or just when ever it wants to?

 

Dry smooth pavement no rain for weeks, just driving along.

 

Cam or crank position sensor.

You better hope its not the crank sensor. Its a pain. The cam sensor is also known as a pick up coil, and is the black disc under the rotor in the distributor.

The crank position is the cheaper of the two, but the tougher job.

Good luck with whichever one you replace.


Oh, and I'm moving this to OEM tech.

 

My ZJ with a 4.0 acted the same as you described, the crank sensor took care of it. Your wife has a good eye for spotting the tach when the engine started acting up, most women would even know what the tach was for.

 

Hearing that makes me proud of my wife!!