Stuttering problem fixed

So when I was on the road in FL I stopped at the Don Garlits museum. When I started driving again the jeep had a horrible stuttering problem, and it was missing on 2 cylinders. The temp gauge was up about 220 or 230 when I got back in...these motors just run hot.
So I stopped under an overpass and popped the hood. Checked all the connections and everything under the hood. Everything seemed to be ok so I wasn't worried and sat there a while. After an hour it started right back up and went 350 miles with no issues.
I got to pensacola and went cruising around, but it got hot again, traffic and a/c and all that stuff. So I called the old man and he said the Haynes said it was the fuel filter. I go to the jeep dealer (fuel filter is apparently a dealer supplied replacement part and not available in the parts stores). Went out to the mechanics area because the parts counter guy said they don't usually sell fuel filters for the 00 model. The mechanic said to check the wires and everything, mentioning the distributor and other parts. So i rented a car and enjoyed my time off. 2 days later I took the jeep out (with out doing ANYTHING) and it ran like a champ, hitting some sandy trails and other areas near pcola. No big deal as of yet this day. Later that afternoon I took my buddy out with me and we went and played in a big flat sand area, full throttle with the a/c on and getting way sideways and just playing. Stopped for a rest and to cool the jeep off and it got hot...I should have took it for a slow cruise to cool it off but I didn't. When it started up it started stuttering and had multiple misses again, BUT when we got it on the road and it got below 220 it started running good again. He's a mechanic again and suggested that we check the wires and coil pack and plugs. Got a new coil pack (distributorless ignition reminder for all older model owners) and a set of Bosch platinum plugs. We gapped the plugs at 35 thou and put a new coil pack on. Started the jeep up and it ran great. I drove it yesterday from pensacola to knoxville, with no issues at all. The motor did get hot a few times when I was going up some hills, but the stuttering never came about again and didn't at all today.

I thought I'd put this up if anyone had this issue and was wondering what one fix was.

Only fuel filter on a '00 is in the gas tank, and you have to drop the tank to get to it. Missing on 2 cylinders kind of makes sense, because the coil pack has 3 coils in it firing two cylinders simulateously off each one in turn. First time I heard of a bad coil pack.

Sounds more like a "heat soak" situation to me.

If you are always running at 220-230 you need to service/upgrade your cooling system.

For the heat soak do a search, but quick recommendation is put a timer on the eFan so it will run for about two minutes after you shut off the engine. Link: http://www.at-fairfax.com/ConstructionElectronics/RelayBoardDelayTimers.htm I recommend the ELK-960.

X2 - heat soak would be much more common than coil pack. And his one day ride is not quite a validation of the "fix".

kf chris. please come back at us in a month or so. Otherwise people will start changing their coil packs needlessly (maybe)

Thanks for the advice. I know how my jeep runs and the issue is fixed. I also have more power and better fuel economy. It did fix the issue for MY jeep.
You guys are fickle here for advice. It's "a fix" but maybe not "THE fix"

joe_peters said:

Sounds more like a "heat soak" situation to me.

If you are always running at 220-230 you need to service/upgrade your cooling system.

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X3, heat soak.

Sounds like a lack of cooling system maintenance leading to heat soak/vapor lock. The fuel pump, fuel pressure regulator, and pickup screen filter are not normally serviced unless they have failed.

kf_chris said:

You guys are fickle here for advice. It's "a fix" but maybe not "THE fix"

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You have written a great blog entry, but you failed to include enough detailed and specific information to provide you with a more complete diagnosis or plan to "fix" the problem.

Also, the technical and diagnostic skills of people on the Forum does vary and not every reply may be correct (mine included).

Tim_MN said:

Also, the technical and diagnostic skills of people on the Forum does vary and not every reply may be correct (mine included).

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Well said! :confused1