Jeep Garage  - Jeep Forum banner
1 - 20 of 21 Posts

·
Registered
Joined
·
24 Posts
Discussion Starter · #1 ·
Hello,
These past few winter months I have had problems with my jeep not idling consistently but sometimes it idles normally. Also during this time it will die, or want to die if I stop at a stop sign to fast. Once I drive a few miles and the engine gets warmed up then it wont want to stall out. I cleaned the throttle body and IAC valve but that did not work. I bought a new IAC valve this weekend but I am still having issues. The new IAC valve did let my jeep idle below 1,000 rpms but it still idles consistently.
Thanks for any help.
 

·
The beast from Brazil
Joined
·
8,310 Posts
Idle issues are mostly due to dirty throttle body and/or IAC motor, or a TPS. Did you check if there was any fault code set by the PCM using the key dance?
You mentioned that with the new IAC the idle is below the 1000 rpm, it should be at 650 rpm. High idle issues or fluctuating idle are mostly caused by the TPS going bad (throttle position sensor).
 

·
Registered
Joined
·
24 Posts
Discussion Starter · #3 ·
I have not tried the key dance, did not know about it. And it idles between the 600 to 800 rpm range when it decides to bounce around.
 

·
The beast from Brazil
Joined
·
8,310 Posts
The key dance works like this: switch ignition switch OFF/ON 3 times and leave it in ON at the third time. The odometer will show "DONE" when all ok, or the stored fault code(s).
If you have a scanner which shows live data, you could check the TPS position (in %) and see if its a steady value or that it changes a bit. When not completely steady, you have to change the TPS.
 

·
Registered
2000 GC
Joined
·
120 Posts
I would try changing the TPS. Mine did the same thing a while back and I changed the TPS and all my problems went away. Hopefully this helps you.
 

·
Registered
Joined
·
57 Posts
Ditto Here!! Except my TB and IAC were horrificlly dirty and sludgy. I also changes the TPS because I was having transmission hunting problems. It is like a brand new truck now!! Idles perfect and shifts perfect!!
Good Luck.
 

·
Registered
Joined
·
24 Posts
Discussion Starter · #11 ·
Well I installed the new TPS and I am still having the same problems. Now I am back to the Rome being around 900.
 

·
The beast from Brazil
Joined
·
8,310 Posts
Does it start normally when cold, or does it have to crank longer then normal?
Is the normal maintenance done in time (plugs, air filter)
 

·
Registered
Joined
·
45 Posts
Not real sure,hopefully Frango or another more experienced member might chime in, would the o2 sensors going to the bad affect the idling?
 

·
The beast from Brazil
Joined
·
8,310 Posts
Have a look for a vacuum leak. Could be a loose hose or damaged hose. For example the PCV valve hose.
In idle the engine will run in closed loop, so uses the O2 sensors for fuel fine trimming. But never heard of a loppy idle due to the O2 sensors.
 

·
Registered
Joined
·
24 Posts
Discussion Starter · #17 ·
Have not looked for a vacuum leak yet. Wouldn't be surprised if that it is since I have had to put new and improved hose clamps on a few other hoses already.
 

·
Registered
Joined
·
11 Posts
Do you only have this issue when its cold? Could also be the intake gaskets. Would explain why it stops stalling when it warms up.
 
1 - 20 of 21 Posts
Top