So I’ve been have a weird idle issue ever since Oct of 2020 and I can’t seem to figure out what the problem is. I’ve replace the TPS and MAP. I’ve also cleaned my IAC Valve several times. I also changed a bunch of fluids and replace spark plug and I’m still having the issue. When I start my Jeep it immediately starts to have a low idle and when I drive in warm places like Las Vegas the idle stays pretty consistent (about 650-750) but when I drive in colder/ higher elevations it drops. I also haven’t gotten any check engine lights (which doesn’t help). The only things I know is that steering pump squeals at high speeds and that my breaks need to be replaced.
Weird idle issue
- Thread starter JacksonH
- Start date
Have you looked at scan tool data ? Do you have scan tool ?
You need to look at coolant temp and air temp at start up. The manifold air temp should be close to ambient air temp and engine coolant temp should be close to if engine is cold.
You kinda got to have some scan tool data on this.
You need to look at coolant temp and air temp at start up. The manifold air temp should be close to ambient air temp and engine coolant temp should be close to if engine is cold.
You kinda got to have some scan tool data on this.
Did you remove the IAC to clean it? If so did you also thoroughly clean its orifice in the throttle body the IAC's plunger fits into
What does jeep have manual or automatic transmission ? Air conditioning?
The powertrain control module at start-up/key on looks at ECT, inlet air temp, throttle position(which you changed) and a few other things,then commands IAC to position! If you have junk in you have junk out,and it doesn't have to set CEL. If sensors are good then go to IAC,clean and wiggle connection while running. A high dollar scan tool will give you IAC counts.
Turn a/C on at idle see if you get rpm bump?
If all input and output is good then IAC could be bad or passage blocked. Did you clean throttle body when you did IAC ?
The powertrain control module at start-up/key on looks at ECT, inlet air temp, throttle position(which you changed) and a few other things,then commands IAC to position! If you have junk in you have junk out,and it doesn't have to set CEL. If sensors are good then go to IAC,clean and wiggle connection while running. A high dollar scan tool will give you IAC counts.
Turn a/C on at idle see if you get rpm bump?
If all input and output is good then IAC could be bad or passage blocked. Did you clean throttle body when you did IAC ?
So I have an automatic and when I turn on the A/C it has no real effect on the idle. The connection seems solid. I also did clean the entire throttle body.
birdsongty1
New Member
After doing anything to do with the idle, do a memory wipe. Disconnect the negative battery terminal and put a jumper on the positive to the negative cable only. Don't let it touch the negative battery terminal! Keep the jumper on for five minutes. After five minutes remove the jumper and reconnect the cable to the negative battery terminal. Start your vehicle and let idle for five minutes and then take it for a drive anytime over tens minutes. This forces you computer to go back to OEM settings and it loses any adjustments. This made my jeep of 20 years old run amazing. Good luck.