I have a 2001 TJ Wrangler with a 4.0L and automatic.
It seems to have a problem only in the summer time. When it gets over 90 degrees I notice that when i drive it for a while on the freeway or town and park it for a while it gets (heat soaked) and when I try and start it it runs REALLY rough like it is missing on several cylinders.. .I have to rev it up to clear it out and I can keep driving.
Today it was 104 degrees and I came off the freeway and stopped at the store for 1/2 hour and went out to start it and it ran really rough and I revved it up to clear it and when I put it into reverse ( A/C ON ) and it died.. I put it back into park shut off the A/C and fired it up and it still idled rough so i just idled it about 400 ft and it cleared up.
I made one more stop in town for about the same time (1/2 hour) and fired it up and it was o.k.. I am thinking maybe it has a leaky fuel injector or two? Or could it be some sensor that makes it do this?
The jeep only has 53,000 miles on it.. I have had this problem for a couple summers now but it is Really getting bad now.... If someone has had this same issue maybe someone can lead me as to what the problem may be.... thanks,
My 2000 Sport did that several summers ago. I would do maintenance on the cooling system if it hasn't been done already, flush, new t-stat and hoses if it needs it. Mine finally got bad enough that it was overheating at idle at long traffic lights. Turned out to be my fan clutch. The heat soak issue also went away when I replaced it.
That must be the recall the stealership wanted to do on mine. They said it was a heat shield to keep leaves from burning on my manifold lol. I told them they are not touching my jeep and passed on it. Cool to know what it really was. Thanks for posting this.
I performed the TSB recommended repair to my Jeep last summer after I was experiencing the same heat soak problems. We just went through a good heat wave and the Jeep ran great with no issues. The part is cheap and the repair isn't difficult by any measure.
Thanks for the info. I ordered the part and will put it on and see if that fixes the problem, I had a feeling it had something to do with the injector overheating and the fuel vaporizing like the old fuel pumps would do they would "Vapor lock" and you use to have to pour cold water on the fuel pump to get the vapor to return to a liquid state.. Will fix it and let you know if there is anymore problems....
I had read the same TSB that C.L. posted and was getting ready to make the mod when the fan clutch failure finally reared it's ugly head. After replacing the fan clutch, the problem went away so I never did do the mod per the TSB.
Well I did the TSB fix and the jeep didn't act up today so it must be ok... I am thinking of using some of the doubled foil plastic bubble insulation and wrapping all the injectors to make them cooler, I think it would be a good thing to make the mall cooler since there is a lot of heat under the hood from the exhaust manifold...
Good to have this info, thanks. This has happen a number of times on an 04 TJ we just purchased a few months ago. First time was a trip to the beach in heavy traffic, got hung up in a bad wreck then beach traffic for 30 miles, got so bad would do it after being stopped at a traffic light.
It's too bad the intake and exhaust manifolds are so close on the 4.0 engine. I've got a mechanical temperature probe located near the intake manifold and have recorded temps over 280F just after shutting down the engine in hot weather.
Actually, since my underhood gauge only reads to 280F, I don't know how much hotter that manifold can get, but the needle sometimes rose past 280F. I actually buried the needle one time and ruined the gauge. I had several gauges in the "past projects" box, so I installed another one and so far it's still working. I helped it out by installed hood vents and an old "past projects" 12-inch radiator fan to exhaust the underhood heat through the vents. Running the fan 10 minutes past shutdown keeps the temps down to 200F or so. I think other underhood components have benefited too, but that's speculation on my part.
Well today was the first day of real driving since I put the "magic sleeve" on fuel injector number 3... well it didn't fix it... yes today was 106 degrees, but when I shut it off after going on the freeway and letting it sit for 20 minutes I started it and it was BAD!!!! I put the gas to the floor to try and clear it and it backfired through the exhaust and studdered and the check engine light came on..... it took it about 45 seconds for it to clear up... this is nuts.... obviously there is a design problem.... I guess I will wrap all my injectors with the double sided foil wrap and fuel rail.... I know a lot of it has to do with the crappy ass gas with the 10% ethanol.... Who ever had that additive idea is a idiot... NOTHING runs good on that stuff.... All I can do is try and wrap everything to keep it from doing it again.....
I picket up the "fix" today and it was one white strip (tube) of whatever, I thought it was two pieces. Should I cut it or what? I noticed that I have a sheet of thick insolation and foil between the exhaust and intake. 2004 TJ Sahara. Is #1 cylinder at the firewall or radiator?
Ok So I wrapped my fuel rail and all fuel injectors in aluminum insulation.. the bubblewrap with foil on both sides... I have had good luck with it displacing heat. I even went so far as the wrap the air intake pipe that goes from the airbox to the throttle body, so the air into the engine will stay cooler. I plan to take it out in a day or two and post my results......
So today was 100 degrees out and I took the same trip over the mountains again on the freeway after wrapping my fuel injectors and fuel rail and air intake tube... This time I had no problems with the heat soak.... looks my fix trumps Chrysler's.... Sorry Chrysler.
I am also suspect that perhaps my fan clutch is out of spec because it doesn't seem to tighten up very tight at temperature so I am going to change it as well and see if that disperses any heat. The temp gauge was at 210 and never got over that while towing a trailer behind so at least it isn't overheating but to err on the side of caution I am going to change the fan clutch and see if that may be part of the reason why it was getting so hot, but when it it between 100-115 degrees outside not much cools anyway...