bryanboonern

I only really notice this problem when wheeling when I turn off the motor the go to restart it. When I do this, I get a terrible miss for a few minutes then it clears itself up. I heard there was a TSB about this but when I looked at it, it did not apply to my year, a 1999. It has not thrown a code and I have not had it plugged up to a computer while doing this, so I don't know what cylinder(s) is misfiring. Anyone know what this could be?

bryanboonern

Nobody??

98 JeepJeep

yours is 99? so you may have a coil pack issue.....

Iant333

No its not a coil issue, all late model XJ's do it and to be honest there isnt a good way to fix it either. Its a cyl 3 misfire though if that's the problem. Whats happens is the cyl 3 fuel injector sits real close to the exhaust manifold and the heat makes it malfunction until it clears itself out.

Edit- 99's dont even have COP ignition. Distributors until 00.

98 JeepJeep

i think Chrysler tried to fix this issue with a little foil heat sheild...i have seen that on many motors between the injectors and the intake....

98 JeepJeep

ya i cant ever remeber the years they switched.....

Iant333

Yeah but it doesnt make much difference. I put a heat shield in there myself and it made almost no difference. I just learned to deal with it, i've never had it so bad it stalls out on me.

98 JeepJeep

swap the injectors for a better set.......

00xj-classic

the problem is the intake manifold.. in 1999 chrysler put the updated and more free flowing intake manifold on the 4.0s.. this causes the heat from the exhaust manifold to rise up to inj#3 causing the fuel to vaporize.. i simply put a little heat sheld AROUND inj#3 and i have no more heat soak issues.. i also have the Heat sheild on top of the intake manifold.. Its really simple and should take you a couple mins..

98 JeepJeep

i run the 00 intake manifold on mine (98) and dont have any issues...but i also have different injectors than a 99+ XJ would have.

Iant333

The injectors arent the problem, its where they are located.

MrJCRod

I had the same problem but I think I fixed it. I ran a bypass switch for the electric fan and around town or in stop and go traffic I leave the fan on. I actually only turn it off on longer highway runs when there is plenty of airflow. With the fan moving air on the driver side where the exhaust and the injectors are, my heat soak problem seems to be fixed. Not one issue since doing the mod. I ran quite a few wires and an extra switch so I have complete control of the fan. I can let the computer control it or I can turn it on whenever I want and I put a kill switch on it so it won't come on at all. That's for when I go through deep water holes. I don't want the fan coming on when it's submerged... Between the fan mod and hood vent I made I am hoping to not have heat soak problems ever again... We'll see how it works come summertime but so far so good....

bryanboonern

Thanks for the good info guys. 00xj-classic, have any pics of those heat shields?

roughridenxj

mine does the same thing. when i am wheeling and let it idle for a little bit or i shut it off for a short period time, it barely runs or it dies and wont start for about 10 min. when it does miss and barely run i can clear it up by tapping the peddle to rev it up. it kinda seems like an injector sticks open and flooding it because i can smell raw fuel.

MasterShakeXJ

i have it on my 01; cylinder 3 misfire. easiest/cheapest solution is to just pop the hood when you stop on the trail. or just let it keep running. or get some kind of aux cooler.