I'm having an issue with high idle, cleaned the IAC, replaced the TPS, cleaned the throttle body (wasn't all that dirty), replaced the engine air temp sensor, and still idles high. The OX sensor was replaced about two months ago, and the CPS was replaced about two years ago.

The only engine codes I WAS getting, were 12 & 25.

It's fine when I do a cold start, and drives fine.

If I turn it back on after it's warmed up, that's when it starts acting up.

It down shifts hard into 1'st gear, and revs up to 1,200-1,500. I put it in neutral and/or park, and let off the break, it still revs high.

I'm at a loss right now and need some advice.

1995, 4.0, autotrans, all after market exhaust (just two months old).

 

Pretty much what mine is doing and no cel on mine

 

replace the IAC.

could be a vacuum leak. normally only the renix models had issues with the intake getting lose, but it is worth a check

 

Spray carb cleaner where the intake meets the head and see if it goes away. This will check for intake leak.

 

I was getting code 25 thrown.



So I started messing with the wires and could hear the idle drop back down. I wasn't getting a code this whole time till just now. I did the seafoam treatment and I have no vacuum leaks.

SHES IDLING NORMAL AGAIN! thanks for the input tho! Really appreciate it.

 

You " started messing with the wires" and the idle came down. Define messing.
Sounds like an electrical connection/wiring problem, and messing with it didnt fix it, it likely just temporarily made contact. Chase the cause for a permanent fix because it will be back...

 

They were getting hit from being next to the fuel rail. Thanks to jeep for putting a harness directly across the manifold. So I took apart a small portion of the harness and separated the wires. It wasn't actually shorting out, they were getting hot and sending wrong signals.

 

Hot*

 

Could be the pic, but several wires seem to be spliced?

 

Ok, well I thought I solved the issue. I've re torqued the manifold bolts, cleaned the O2 sensor, even sprayed carb cleaner along the manifold gasket. I'm positive there isn't any air leaks.

I'm still getting codes 24/25 being thrown. I ordered a new TPS and MAT sensor connector to re wire the sensors. Seeing how code 25 says it's a short.