[Jeep79&98]

Originally Posted by surf1324

I found this post and it sounds like this guy is having the same problem that I am. This description sounds like my jeep to a "T"... I need help...


"I have a problem with my 96 cherokee (130k, 4.0 I6) that seems to stump a lot of gearheads that I know, I'll tell you as many details as needed, hopefully someone has had a similar experience and can help:

When accelerating to cruising speed, ONLY the first time after startup, the engine suddenly bogs in rpm and loses power somewhere between 15-35 mph (sorry, no tach). This power lost can last anywhere from 1 second to 4 or 5 seconds, and only seems to get worse if I press on the gas more. When it does pick back up, it REALLY picks up and I can feel a very noticeable difference in power. As I mentioned, it only does it within seconds of starting the vehicle, and accelerating the first time after startup. When I do accelerate, it make a popping noise from the engine or mabye the air cleaner.

It is fairly sparatic on doing this, not every time, sometimes it can go days without doing it, then sometimes 3 times in a row one day (upon consecutive starts).

Seems to do it whether engine is hot or cold.

Air filter is good.

Fuel filter replaced about 20k ago.

Seems to be independent of fuel level in tank.

Tranny fluid level and color is good, flushed about 30k ago.

New TPS sensor about 35k ago

Any help would be great."

I have exactly the same problem as described in the previous post. Since last posting, I have replaced the TPS, MAP sensor, and IAC valve. I have also pulled the injectors and cleaned the intake and injectors. I have been told to change the fuel filter but it does not make sense to since it only happens once after I start the car. If it was the filter, I would think that it would be a continuous problem instead of a one time thing after starting. Mabye another kind of sensor? I need help, it's driving me crazy. It can be very dangerous when getting on the freeway right after starting the car. I do this sometimes and it just decelerates on me.

I Have a 98 jgc and I am having the same problem I cant figure out what is happening I just recently changed the catatlyc Converter and the O2 sensors it improved a little but still hesitating. No codes on the computer Need some Help!