2000 Up Xj Cherokee Heat Soak Issues

[sinkrun]

Anyone on here have any info on fixes for the heat soak #3 Cyl misfire issue. Theres info all over the net but not much actual info on A true fix.

[HOrnbrod]

Recall Reason FUEL SYSTEM, GASOLINE:FUEL INJECTION SYSTEM:INJECTORS

Recall Date APR 08, 2002

Model Affected CHEROKEE

Potential Units Affected 1115322

 

Recall Summary

ON CERTAIN SPORT UTILITY VEHICLES EQUIPPED WITH A 4.0L ENGINE ONLY, THE DESIGN OF THE INTAKE AND EXHAUST MANIFOLDS COULD ALLOW DEBRIS TO ACCUMULATE AT THE #3 CYLINDER LOCATION.

 

Consequence

THIS COULD RESULT IN A VEHICLE FIRE.

 

Remedy

DEALERS WILL INSTALL A MANIFOLD SHIELD TO MODIFY THE AIR FLOW CHARACTERISTICS AND TO PREVENT THE ACCUMULATION OF DEBRIS IN THE AREA OF THE #3 CYLINDER. OWNER NOTIFICATION BEGAN MAY 13, 2002. OWNERS WHO TAKE THEIR VEHICLES TO AN AUTHORIZED DEALER ON AN AGREED UPON SERVICE DATE AND DO NOT RECEIVE THE FREE REMEDY WITHIN A REASONABLE TIME SHOULD CONTACT DAIMLERCHRYSLER AT 1-800-853-1403.

 

Notes

DAIMLERCHRYSLER CORPORATION B06

Quote:

This bulletin is supplied as technical information only and is not an authorization for repair. No part of this publication may be reproduced, stored in a retreival system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, or otherwise, without written permission of DaimlerChrysler Corporation.

 

THIS BULLETIN SUPERSEDES TECHNICAL SERVICE BULLETIN 18-027-02,

DATED SEPTEMBER 06, 2002, WHICH SHOULD BE REMOVED FROM

YOUR FILES. THIS IS A COMPLETE REVISION AND NO ASTERISKS

HAVE BEEN USED TO HIGHLIGHT REVISIONS.

 

SUBJECT:

4.0L Rough Engine Idle After Restart Following A Hot Soak

 

OVERVIEW:

This bulletin involves the installation of a fuel injector insulator sleeve.

 

MODELS:

2000-2004 (TJ) Wrangler (Domestic and International Markets)

1999-2004 (WJ) Grand Cherokee (Domestic and International Markets)

2001-2004 (WG) Grand Cherokee (International Market)

2000-2001 (XJ) Jeep Cherokee (Domestic and International Markets)

NOTE: This bulletin applies to vehicles equipped with a 4.0L engine (sales code = ERH)

 

SYMPTOM/CONDITION:

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.

 

DIAGNOSIS:

1. 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:

Qty. Part No. Description

 

1 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.

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).

 

POLICY:

Reimbursable within the provisions of the warranty.

TIME ALLOWANCE: 0.2hrs

 

FAILURE CODE:

AM Authorized Modification

 

The "cure" is an intake manifold heat shield and a wrap around the affected injector, usually #3. The part number is highlighted in RED above is the injector wrap.  The debris shield mentioned above is part number is CBXCB060, and pictured below. I put one on when I installed my 2001 intake manifold. Both are like $2-$3 at the dealer.

 

[Truckcom]

This describes exactly what my wife's 1999 XJ has done since we bought it 3 years ago. Otherwise it runs perfectly, so I have to assume that this situation could apply to other Cherokees as well. Thanks for the info.

[terrawombat]

This describes exactly what my wife's 1999 XJ has done since we bought it 3 years ago. Otherwise it runs perfectly, so I have to assume that this situation could apply to other Cherokees as well. Thanks for the info.

The heatsoak issues came about when Chryco retrofitted the exhaust system with two pre-cats directly under the intake manifold.  This officially happened on the 2000 and 2001 Cherokee's, but I have seen a very late model 1999 that had it as well (but it could have been swapped in...not sure why you'd ever want to swap pre-cat's on).  The pre-cats get nice and toasty and when you shut the vehicle down, the heat from them rises up and cooks the injectors.  I had the heat shield on my '01 XJ for a while, but it didn't really help much and I yanked it when I did an injector swap.  The only time the problem occurred was when the vehicle was driven, shut down and then restarted within 10-15 minutes.  The engine would always start, it would just stumble for about 10-15 seconds and then would smooth right out.