89whiteXJ

Ok So when driving and doing over a bridge or needing to speed up I step on the gas the jeep down shifts and some times depending on the power needed it will rev up to almost 7k. My red line starts at like 5k. What is the deal with that?
Thanks

Abovetimberline

Does it fell like 7000k rpm? that is alot for these engines,if it is actually that high it will spin a bearing or worse like connecting rods.
I think you would back off the throttle if it got that high actually.

89whiteXJ

maybe its not is there a chance the tach could be wrong? it seems to idle fine. I dont think it seems to be reving up that high but maybe. I would think it would have a rev limiter that would stop that.

redrustbucket91

Cherokees do have a rev limiter. They usually rev out at about 5200 to 5300 rpm. You might have an electrical problem with your tach.

Abovetimberline

i would suspect the tach,when mine has reached 5k it concerns me and I back off,only happened a couple of times. the only thing that would allow this is your trany or a bad clutch,and if they were in that bad they would not move your jeep.

NewXJaddict

not trying to jack the thread, but it reminds me of something similar mine does. Every once in a while when I start it up it revs high like mad and wont come down. I have cleaned out the throttle body....mainly by spraying throttle body cleaner in the intake. A friend of mine said its probably a cold start valve?

cole93maxxxj

ya. you need a new idle air control valve ! hapened to me

89whiteXJ

I have this prob too. What I do is unplug the TPS and then it lowers. I plug it back and and runs ok. You might need a new TPS. There used to be a technical service bulletin on this problem. Jeep used to have to put new one on.