98 gc 4.0..... the rpms shoot up n down at low speeds but when I step on it, it runs fine whtcan it be, I need HELP

 

is the cel on?

 

Cel?????? I am new to this soo the short terms are a lil hard

 

i figured it out and it is on how do i turn it off

 

cel.., check engine light
you dont just want to turn it off. thats not going to help. you need to find out WHY its on. go to your nearest AutoZone or parts store that offers free diagnostics. they can "pull the code" for you. this will give you some indication of what might be wrong. I had the same kinda problem but with some spitting and sputtering and back firing through the throttle body. there are a few different things that might cause this...,
1) coolant temp sensor. (cts)
2) throttle position sensor (tps)
3) crank position sensor (cps)
4) map sensor (?)
5) oxygen sensors (o2) there may be 2 depending on the year of your xj.

this seems to be a common problem.., there a lot of threads with alot of different advice.
could be as simple as a bad connection to one or more of the above mentioned sensors.
could be a vacuum leak.
mine ended up being the front o2 sensor. (about $80). I just unplugged it for now and it runs fine (runs pretty much normal) but still plan on replacing it
soon.

good luck!

could I have possibly missed anything? Anyone?

 

Thanks for the help I am gonna go to autozone when off of work

 

Found out what was wrong with it...... its the pick up coil, neutral safety switch, and speed sensor