[gregsjeep13]

I took my jeep and 5x8 trailer with a pretty heavy load to the dump and now my 97 Jeep wrangler 4.0 (5 speed) is idling high (2,000 to 2200 rpms) when I am just sitting, as soon as I start moving it goes back to normal? If I put it in second and go real slow the rpms go down below 1,000. It seems to run normal while driving but every time I come to a stop it stays up at 2,000 (+) rpms. The cable seems to have a little slop but it seems like that would make it idle at low rpms? I not the most mechanical guy so any suggestions would be greatly appreciated.

 

[gregsjeep13]

Any ideas

 

[Trigg]

There are several threads about cleaning the idle air controller IAC. It's attached to the intake.

 

[colinwilson]

I took my jeep and 5x8 trailer with a pretty heavy load to the dump and now my 97 Jeep wrangler 4.0 (5 speed) is idling high (2,000 to 2200 rpms) when I am just sitting, as soon as I start moving it goes back to normal? If I put it in second and go real slow the rpms go down below 1,000. It seems to run normal while driving but every time I come to a stop it stays up at 2,000 (+) rpms. The cable seems to have a little slop but it seems like that would make it idle at low rpms? I not the most mechanical guy so any suggestions would be greatly appreciated.

I'm having this same issue. I replaced the IAC and it helped a lot and I'm at 1,000 rpms now. I tested the TPS and its bad so I'll replace that and it should get to normal.

 

[gregsjeep13]

The rpms are down to 800 when idling? I did not do anything to make this happen but now the check engine light is on. It never came on when I was having the rpm issue.

Is there a unit I can buy that will give me the code issue?

I will look into the IAC cleaning also but I am guessing I will need to clear the codes also.

 

[gregsjeep13]

My friend had a code reader and it gave me a P1398 code. I also read where you can turn the key on 3 times quickly and that will give codes on your dash. I did this and the codes it gave me were 12 then 11 then 55. Can anyone help me with these codes? Thanks for your help.