I have a 1997 Jeep Cherokee with 4.0 So last week I have drove the Jeep more than normal. Drove it around 300 miles and it started out fine at the beginning of the week. A few days in it started randomly idling high ( around 2000) when in park and you could feel the high idle when in drive at a stop light. It has also started cutting out some when driving. Just random little jerks that sound like its missing.

In the last few months I have replaced plug, wires and cap, cps, tps, map and o2 sensor. The only one I haven't replaced would be the IAC but I have cleaned it and the throttle body. The IAC looked a little rough whenever it was cleaned. Is that something that would cause the high idle and cutting out?

 

Have you checked for a vacuum leak? I know my 89 XJ does the same thing and I have cracks in my exhaust manifold... Also have you adjusted the TPS properly? If you don't know how I'm sure we can help out with that! Good luck!

 

I have done a quick check but haven't had a chance to look really well. I have never adjusted the TPS or knew that was possible. How do you do that?

 

I checked for vacuum leak and had it ran for codes today (light doesn't work) could not find anything. It does it more when its cold but does it all of the time. It will just cut out sometimes once sometimes two or three times.
Any ideas on what the issue could be? It had done this before and I replaced the already new 02 sensor hoping that it was a faulty sensor. It seemed a little better for a few weeks but has been back to doing it but not as bad.

 

You don't.

'97 TPS is non-adjustable.

Have you checked your fuel pressure at the fuel rail using a test gauge?

You should see 49.2 psi +/- 5 psi (engine running at idle and under acceleration).

 

Ya I have checked it twice and it was good both times. Still no idea what it is! Seems to be getting a little worse too

 

I imagine it would if it were stuck open all the time. May cause a lean condition that the PCM can't correct.

Since you've changed everything under the hood you may as well change the IAC as well.

Did you mean "plugs" not "plug", and both O2S instead of just the one?

 

i know this is a really old post but this is the identical issue I’m having. Any chance the OP is still active?

 

You can PM or Private Message the person you want to talk to...
i believe it also gets sent to their email/text as a notification.



Good luck, God Bless.