A ? for the late model guys......

I have an '01 XJ that so far in warm to hot weather, if the Jeep sits for a short time with the engine off(like running into the store for say 5-10 min) I start it up and it runs pretty rough, I've been told it's from the #3(?) injector over heating and fowling out, once it gets fuel pumping though it it cools down and acts normal. I have noticed that one of the injectors (never really paid attn to which one), is wrapped in some sort of cardboard, an insulator my guess, the same person told me that was Chrysler's fix for the problem, but it doesn't seem to be doing the job. Is all this true and is there a fix beyond what has been already done?

And for the guys with hood vents, did that help much?

I have the same prob. Its a pain in the a$$. Search here for "misfire". Im thinking of getting some of that heat wrap and protecting the whole fuel rail and the injectors. But yea, crysler did have a tsb for it and the fix was in insulator around the injector as well as a lowet temp t-stat and a reflash of the computer cooling settings.

I read about that, didn't the insulator cause problems too?

heat soak

[FONT=&quot]It's a problem that just about all 2000-2001s have.
It's really acts up after a long climb in 4-low when you get to the top and shut down for a short while. It usually lights the CEL and show a misfire on #3 and sometimes several other cylinders. My XJ has a Scan Gauge that has the ability to clear codes as well as monitor the OBDII sensors. It gets used on most off road trips.
http://www.scangauge.com/
I have added insulators under all the injectors and a switch and relay to turn the aux fan on so I can leave it running after the engine is turned off. These mods have helped a lot but have not totally cured the problem.
The newer models have a lot of extra heat caused by the mini-cats, located at the bottom of the exhaust manifold.
I should have bought a 1999 model. Maybe next time.[/FONT]

I plan on doing a lot of mods next summer, hood vent's, a swap for an '05 head, and a JKS header are on the list. Wrapping that header should help too, especially combined with the hood vents. I may look into an aluminum radiator and electric fan too.

Heres a response I got On JF:


I had the same problem, and the CEL light would trigger and it just so happened I bought seafoam that day and sea foamed my engine and put some in the gas tank and haven't had a problem since, you mind as well give it a try since it's $5. But I'm sure someone may agree or disagree w/ me, thats just my 2 cents.

EDIT: heres what Silver XJ posted on my topic: Original Post: http://www.jeepforum.com/forum/showthread.php?t=544765:

Quote:
http://www.wjjeeps.com/tsb/tsb_wj_1803103.pdf
TSB
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.


TSB for the cold start rough idle and P0303 code: TSB 18-010-01