Odd IAC Retract Issue
11-14-2015, 10:39 AM
#1
Junior Member
Thread Starter
Join Date: Nov 2015
Location: Central Arkansas
Posts: 51
Likes: 0
Received 2 Likes
on
1 Post
Year: Started as a 1987
Model: Cherokee
Engine: 4.0 Renix
Odd IAC Retract Issue
Vehicle is a 1987 Cherokee with the 4.0 engine.
The problem that I am having is that the Idle Air Control valve/Idle Stepper Motor is not retracting when the engine is turned off with the key. The IAC/ISM only retracts if the engine fails to start during cranking or dies while running. This is causing a very rough idle at start up. Sometimes the engine sputters and dies after start up.
I checked the sensor ground resistance and it was a whopping 130 Ohms! I cleaned grounds, cleaned the C101 connector, and soldered the spliced grounds in the wire harness together. Now the sensor ground resistance is around .8 ohms.
This is the second new IAC and the problem also happens with the original IAC. The power latch relay has been both replaced with new relays and swapped with known working relays.
What could cause the IAC to only retract when the engine dies or fails to start and not when the engine is turned off with the key?
The problem that I am having is that the Idle Air Control valve/Idle Stepper Motor is not retracting when the engine is turned off with the key. The IAC/ISM only retracts if the engine fails to start during cranking or dies while running. This is causing a very rough idle at start up. Sometimes the engine sputters and dies after start up.
I checked the sensor ground resistance and it was a whopping 130 Ohms! I cleaned grounds, cleaned the C101 connector, and soldered the spliced grounds in the wire harness together. Now the sensor ground resistance is around .8 ohms.
This is the second new IAC and the problem also happens with the original IAC. The power latch relay has been both replaced with new relays and swapped with known working relays.
What could cause the IAC to only retract when the engine dies or fails to start and not when the engine is turned off with the key?
11-14-2015, 01:06 PM
#2
::CF Moderator::
Join Date: Aug 2011
Location: Prescott, Az
Posts: 43,971
Received 1,559 Likes
on
1,263 Posts
Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
Great job so far!!
Because the ECU retracts the IAC?
Because the ECU retracts the IAC?
Thread
Thread Starter
Forum
Replies
Last Post
jdtorque
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here
6
03-27-2024 07:07 AM
02809bristol
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here
2
10-25-2015 12:16 AM
bbhudd
Stock Grand Cherokee Tech. All ZJ/WJ/WK Non-modified/stock questions go here!
1
10-22-2015 07:08 AM
Doogluus88
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here
5
10-19-2015 05:49 PM
Hewittxj
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here
7
10-18-2015 09:49 AM
Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)