Rough idle and stalling. Throws intermittent cps code
#1
Newbie
Thread Starter
Join Date: Dec 2020
Posts: 2
Likes: 0
Received 0 Likes
on
0 Posts
Model: Cherokee (XJ)
Rough idle and stalling. Throws intermittent cps code
What's going on everyone, I have a 2000 xj 4.0l as stock as they come in reference to the powertrain. I recently did a big head job on the motor, resurfaced, valve job, pressure tested. The 9's. Put it all back together and it drove fine until the following morning it drove for about 45 mins and it started jumping on the rpms at idle. Pulled the code and as the title says I got cps. I replaced the oil driver and the cam sensor with oem parts straight from the factory. Didn't solve the problem. Adjusted the oil driver while it ran to see if retarding or advancing the timing would solve it. It didn't. Replaced the crankshaft position sensor and it didn't solve it. Im lost as to what to try next. Read some threads about replacing the pcm but I rather stay away from that as long as possible. If any xj wizards see this your recommendations are much appreciated.
#3
CF Veteran
Join Date: Oct 2015
Posts: 7,412
Likes: 0
Received 1,557 Likes
on
1,197 Posts
Year: 2000
Model: Cherokee (XJ)
What Roler asked.
How long before the problem popped up?
And you said you used factory parts for the cam sensor and oil driver but did not specify what you used for the CPS.
On a side note.
When you say oil driver you mean #4 at the illustration, 5083881AA, at this link?
https://www.moparpartsgiant.com/part...agram=00i66982
Curious as to where you found a factory one.
How long before the problem popped up?
And you said you used factory parts for the cam sensor and oil driver but did not specify what you used for the CPS.
On a side note.
When you say oil driver you mean #4 at the illustration, 5083881AA, at this link?
https://www.moparpartsgiant.com/part...agram=00i66982
Curious as to where you found a factory one.
#4
Newbie
Join Date: Feb 2021
Location: Ontario
Posts: 6
Likes: 0
Received 1 Like
on
1 Post
Year: 2000
Model: Cherokee (XJ)
Engine: 4.0L
Might be a long shot be do a compression test and leak down test. My XJ is currently doing the same at cold starts. A compression test has shown me that I have a cylinder that has very low compression.
#5
Senior Member
The intermittent symptom sounds like it could be related to the crankshaft position sensor (located on bell housing). A fault in that circuit can cause RPM to drop out and have no OBDII codes displayed.
* Verify that when reinstalling the head you put a good condition ground strap back on that goes from the left rear head bolt to the firewall
* When putting the head on there is a chance the wire to the crank position sensor was damaged. I recall it routes very close to the left rear corner of the head and I have heard of cases where the wire was pinched or otherwise damaged in the process of getting the head back on.
* Verify that the both ends of the connector and pins are OK and connector is fully seated. Look for a bent or pushed in pin
* Verify that the crank position sensor is installed correctly and securely bolted in place.
* If you have a heavy key ring with lots of weight hanging on the ignition key stop doing that.
* Verify that when reinstalling the head you put a good condition ground strap back on that goes from the left rear head bolt to the firewall
* When putting the head on there is a chance the wire to the crank position sensor was damaged. I recall it routes very close to the left rear corner of the head and I have heard of cases where the wire was pinched or otherwise damaged in the process of getting the head back on.
* Verify that the both ends of the connector and pins are OK and connector is fully seated. Look for a bent or pushed in pin
* Verify that the crank position sensor is installed correctly and securely bolted in place.
* If you have a heavy key ring with lots of weight hanging on the ignition key stop doing that.
Thread
Thread Starter
Forum
Replies
Last Post
Wesleytayyy1
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here
1
07-17-2018 01:07 PM
SlickXJ
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here
3
06-29-2015 10:26 AM
corndog
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here
16
09-29-2014 10:08 AM
oldschool01
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here
1
06-14-2014 03:42 PM
Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)