MN-Jeep.com Forums
Go Back   MN-Jeep.com Forums > Main > Technical Discussions
Register FAQ Members List CalendarGallery Mark Forums Read

Reply
 
Thread Tools
Old 06-15-2005, 03:48 PM   #1
MikeyB
Moderator
 
MikeyB's Avatar
 
Join Date: Oct 2004
Location: Apple Valley
Posts: 2,350
Default Rough Idle After Restart on Newer XJs

I know a lot of people have this issue so I thought I would post something.....




There has been quite a few posts on several forums about 2000-2001 XJ's with very rough idle on cold mornings and I've seen where individuals took their XJ/TJ's in to get looked at and the fix was a PCM software UPDATE. Here is a tsb that I initially spotted on www.wjjeeps.com to back that up (give credit where it's due):
------------------------------------------------------------------------------------------
1801301 - ROUGH IDLE AT COLD TEMPERATURES
Date: 06/11/01

Model Year(s): 2000

Description: Some vehicle engines may exhibit a rough idle and / or Malfunction Indicator Lamp (MIL) light on condition upon initial start-up after a cold soak when temperatures are below 50 degrees F (10 degrees c). This bulletin involves selectively erasing and reprogramming the Powertrain Control Module (PCM) with new software (Cal level 00Cal15C).
------------------------------------------------------------------------------------------

1801001 - ROUGH IDLE AT COLD TEMPERATURES
Date: 04/20/01
Model year(s): 2001

Description:THIS BULLETIN APPLIES TO VEHICLES EQUIPPED WITH A 4.0L (ERH) ENGINE BUILT PRIOR TO APRIL 30, 2001 AND CALIBRATION LEVEL PRIOR TO (LESS OR LOWER THAN) THOSE LISTED IN THE OVERVIEW ABOVE. This bulletin involves selectively erasing and reprogramming the Powertrain Control Module (PCM) with new software (WJ/TJ — calibration level 01Cal14C, XJ — calibration level 15B.)

Details: Some vehicle engines may exhibit a rough idle and/or MIL light “on” condition upon initial start-up after a cold soak when temperatures are below 50°F (10°C).
-------------------------------------------------------------------------------------------
Some may experience a multiple misfire, here is the tsb for that:

0900303 - 4.0L MULTIPLE CYLINDER MISFIRE
Date: 08/01/03

Model Year(s): 1999-2004

Description: NOTE: THIS BULLETIN APPLIES TO VEHICLES EQUIPPED WITH A 4.0L ENGINE. This bulletin involves inspection of all engine exhaust valves and a decarbonizing procedure if necessary.

Details: The customer may experience an incident of engine misfire during certain vehicle operating conditions. The misfire may occur when the vehicle is operated between 50 - 70 MPH and under light loading conditions, e.g. slight uphill road grades. This condition may occur at all ambient conditions, but is more noticeable when ambient conditions are less than 0 C (32 F).

If the vehicle is equipped with On-Board Diagnostic (OBD), a MIL illumination may also have occurred due to Diagnostic Trouble Code (DTC) P0300 - Multiple Cylinder Misfire. Various single cylinder misfire DTC’s may also be present. If the frequency of misfire is high the Powertrain Control Module (PCM) may place the engine in “Limp-In” mode.

The misfire condition may be caused by one or more engine exhaust valves that are slow to close. Late closure of an exhaust valve may be the result of no valve rotation and associated build up of carbon on the exhaust valve stem.

This condition may occur when the engine is not allowed to run at engine RPM’s that are greater than 3,200 RPM. At 3,200 RPM or higher the engine exhaust valves will rotate if not impeded by high carbon deposits. Low engine RPM’s and high carbon deposits are associated with short trip driving where the vehicle engine is not allowed to fully warm to normal engine operating temperatures. Cold ambient temperatures will increase engine warm-up time and add to the opportunity of carbon deposit build-up on the stem of the engine exhaust valve.
---------------------------------------------------------------------------------------------
another:
1803103 - 4.0L ROUGH ENGINE IDLE AFTER RESTART FOLLOWING A HOT SOAK
Date: 09/05/03 (supercedes 1802702 dated 09/06/02)

Model Year(s): 1999-2004

Description: NOTE: This bulletin applies to vehicles equipped with a 4.0L engine. This bulletin involves the installation of a fuel injector insulator sleeve.

Details: Customers may describe a 20 to 30 second rough idle following the restart of a heat soaked engine. This condition may be most noticeable when the engine is restarted following a prior 10 to 20 minute heat soak in hot ambient conditions of approximately 32 C (90ºF) or higher. This condition may be consistent with short city stop-and-go driving trips and can be aggravated by the use of fuel with a high ethanol content. Depending upon various conditions a MIL may occur due to DTC P0303 - Cylinder #3 Misfire.

This condition may be caused by heat from the exhaust manifold that following engine shut down migrates to the area around injector #3 and causes fuel vapor to form within the injector. This in turn may cause a momentary misfire of cylinder #3 until the fuel vapor is cleared of injector #3. The insulator sleeve lowers the injector #3 temperature to a point below which the fuel will not normally vaporize.

If vehicle exhibits a rough idle, and if a misfire of cylinder #3 is observed following a 10 to 20 minute hot soak, perform the Repair Procedure.

Parts required:
56028371AA Ignition Wire Shield

Repair procedure:
1. Cut insulator sleeve, p/n 56028371AA, to make two (2) insulator sleeves about 25-30 mm (1 in.) in length. See diagram.
2. Install one sleeve around injector #3, with the slit on the upward facing side of the injector. Install the other sleeve with the slit on the downward facing side of the injector.
3. Confirm sleeve is flush to intake manifold surface around injector.
4. Check injector #3 wire and ensure that the injector is rotated to a 2 o'clock position (from driver’s side of vehicle).

Last edited by MikeyB; 06-15-2005 at 03:50 PM.
MikeyB is offline   Reply With Quote
Old 06-16-2005, 11:14 AM   #2
Rand McNally
Mall Crawler
 
Join Date: Jan 2005
Location: St Paul, MN
Posts: 24
Default

I have a 2001 with the same rough idle problem. After letting the engine reach peak operating temp and then shutting down for around 10 minutes it runs like crap. Apparently that is because it is now a 5 cylinder since the #3 fuel injector gets hydrolocked. I contacted Park Jeep about this and they said it wasn't a recall, but that here was a fix. I paid $22 to have them wrap some heat shield around the #3 injector. Guess what, still does it. Either Park Jeep techs are morons (I think so because of many other issues they "can't fix") or this really isn't a fix.

Let me know if anyone has any other ideas to solve this problem.
Rand McNally is offline   Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump




All times are GMT -5. The time now is 06:06 PM.


Powered by vBulletin® Version 3.8.8
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Site contents are copyright ©2002-2013 MN-Jeep.com