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  #1  
Old October 23rd, 2010, 10:20
cfishman cfishman is offline
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Hot after shutting off, rough start

2001 4wd, 4.0, Auto

Jeep is cooling fine during normal operation. With AC on or off is fine. Stays in the 195 to 210 mark. Checked coolant - ok.
After parking the jeep, at re-start (20 min later) temp gauge at 230's rough idle - check engine light. Dont hear electric fan run.
Did search on heat soak - wonder if this is it? Whats the EZ fix?
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  #2  
Old October 23rd, 2010, 10:29
brooksjr brooksjr is offline
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Re: Hot after shutting off, rough start

Quote:
Originally Posted by cfishman View Post
2001 4wd, 4.0, Auto

Jeep is cooling fine during normal operation. With AC on or off is fine. Stays in the 195 to 210 mark. Checked coolant - ok.
After parking the jeep, at re-start (20 min later) temp gauge at 230's rough idle - check engine light. Dont hear electric fan run.
Did search on heat soak - wonder if this is it? Whats the EZ fix?
My 2000 does the same thing after doing a little trail riding so I'm curious about what the cause is as well.
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  #3  
Old October 23rd, 2010, 10:37
Mad Steez's Avatar
Mad Steez Mad Steez is offline
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Re: Hot after shutting off, rough start

I have similar problems. did a little research and the awesome joe peters had this to say

Quote:
Originally Posted by joe_peters View Post
BS fix.

It gets too hot in the engine bay, and Chryco fix is to wrap the injector. Road apples!

If you want to confirm if you have heat soak--drive your vehicle until it is good and hot. Park, shut off the engine, and open the hood for about 30 minutes. Restart the engine. If the symptoms are gone, you have heat soak. The only fix is to reduce the under-hood temperature.

Most other manufacturers that encountered this problem simply added a timer circuit in the efan to allow it to run when the engine is off for a short time to reduce the under-hood temperature. Chryco--a cheap piece of insulation.

The heat soak issue for the 1999-01 XJ is due to a number of issues. Redesign of the fuel system eliminating the return line from the fuel rail was a start, followed by the redesign of the manifolds, and compounded on some XJs with the addition of the 50-state emissions package--two pre-cats in the exhaust manifold right under the injectors.

another change Chryco had was to change from Champion plugs to NGK plugs in the effected model years.

I would recommend you come up with a way to reduce your under-hood temperatures. You can install an after-market timer to the efan circuit. Here is a link: http://www.at-fairfax.com/P1786-ELK-960.htm

Good luck.
Try this and see what happens. if it still occurs, you can rule out the heat factor

Other possible solution

Quote:
Originally Posted by chris420 View Post
The shaking is probably vapor lock. 1803103 - 4.0lt Rough Idle After Start Following A Hot Soak Date: 09/05/03 Model Year 1999-2004 Description Note: This bulletin involves the istallation of a fuel injector insulator sleeve.

Details : Customer may describe a 20 to 30 second rough idle following the restart of a heat soaked engine. This condition may be noticeable when the engine is restarted following a prior 10 to 20 minute heat soak in hot ambient conditions of approximately 32 C (90 degrees) or higher. This condition may be consistent with short city stop and go driving trips and can be aggrevated by the use of fuel with high ethonal 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 vapour to momentary misfire of cylinder #3 until fuel vapor is cleared of injector #3 temperature to a point below which the fuel will not normally vaporize.

If the vehicle exhibits a rough idle, and if a misfire of cylinder #3 is observed following a 10-20 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 25-33 mm (1") in lenght
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.

Last edited by Mad Steez; October 23rd, 2010 at 10:47.
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  #4  
Old October 23rd, 2010, 13:52
birchlakeXJ's Avatar
birchlakeXJ birchlakeXJ is offline
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Re: Hot after shutting off, rough start

Does sound like heat soak, especially if you put a code reader on your computer and it reads a "cylinder 3 misfire".

That factory fix of insulating injector #3 is pretty lame in my opinion. Doesn't make much of a difference for many.
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Old October 26th, 2010, 10:49
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CMAHON CMAHON is offline
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Re: Hot after shutting off, rough start

i have same (ish) problem w/ my 01. the info awsome joe gave is good and the second part i have already done w/ no help but has anyone (themself) had this problem and actually fix it themself? plenty to read on the subject but not a one with an actual conclusion.
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