High Idle(IAC?)
#1
Newbie
Thread Starter
Join Date: Aug 2014
Location: Minneapolis
Posts: 8
Likes: 0
Received 0 Likes
on
0 Posts
Year: 1998
Model: Cherokee
Engine: 4.0
High Idle(IAC?)
I've been dealing with a high idle for a few months and can not figure it out. It is a 1998 cherokee 4.0. She idles at about 1500rpm with its old IAC in. I bought a orielly's one and it jumped it up to nearly 3k, so I returned that and assumed it was junk. So this time I bought a MOPAR IAC and it sends my RPMS up to around 2500. The pintle does NOT move in the old one or the new one. and the old one is definitely extended out further. I tried resetting the ECU but still acts the same.
Any help here would be appreciated.
Any help here would be appreciated.
#2
Newbie
Thread Starter
Join Date: Aug 2014
Location: Minneapolis
Posts: 8
Likes: 0
Received 0 Likes
on
0 Posts
Year: 1998
Model: Cherokee
Engine: 4.0
Did a little more testing. tested the voltage at the harness and 3/4 pins read 0, the 2nd one read 1.3. So I am assuming I am not getting power to it. I am going to try a spare ECM out of a parts vehicle to see if that works before tracing the wires.
These are the only ideas I have
These are the only ideas I have
#4
CF Veteran
Join Date: Apr 2012
Location: Wisconsin
Posts: 5,302
Likes: 0
Received 21 Likes
on
18 Posts
Model: Cherokee
IAC is a stepper motor so there won't be a signal there unless the ECU is commanding it to move. Sounds like yours isn't if the idle runs high with a new valve (with it's pintle pulled in) and lower with the old valve. The ECU should correct their position within a few moments.
You could check wiring continuity from the plug back to the four IAC Drivers in the PCM. Drawing:
.
You could check wiring continuity from the plug back to the four IAC Drivers in the PCM. Drawing:
.
Thread
Thread Starter
Forum
Replies
Last Post
Vanderbeen
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here
4
03-13-2016 06:57 PM
peterchi
Stock Grand Cherokee Tech. All ZJ/WJ/WK Non-modified/stock questions go here!
1
03-06-2016 06:34 PM
Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)