RTorrez1

1998, Cherokee XJ Sport, 4.0, auto trans, 4x4 This is my daily driver.
I had my had gasket fail and over heat. Now I have it all back together it will run but it runs real rough at idle. At 1000 rpms and higher it runs smooth. It even wants to stall at a stop sign unless i give it some gas to keep the rpms up.
I have good spark and fuel pressure and all injectors are responding. I'm lost and need to get it up and running as soon as possible.
Any help would be appreciated.
Thanks in advance.

dans98xj

if it over heated it could have warped the head. Did you have the head and block checked for flatness before the new gasket went on? i would also check the intake/exhaust manifold gasket for leaks. It could also be something simple like a sticking IAC motor or a bad TPS.

RTorrez1

I should have mentioned that. Everything checked out fine just a bad spot on the gasket between #5 piston and the water jacket. i will check out the IAC and TPS.

Fred/N0AZZ

Check all vacuum lines for damage or not being connected properly.

RTorrez1

Ok, I rechecked everything and all hoses are fine. I also removed and cleaned the throttle body, tps and iac. Still running rough but not stalling out when idling in gear.
Also, I am not getting any codes at all.

dans98xj

i know it is a pain it might not hurt to just go over and re-torque the head. there could be some compression leakage into the water jacket. is there any bubbles coming out of the radiator when it is running? before you do that try a compression test and see what the results are.

RTorrez1

It is a pain! Mainly because it took me 4 days to in stall the head the first time around. I was only able to work on it a couple of hours at a time. It sucks having a bad back that won't let you do a quick and simple job that normally take a couple of hours.
Also, there is no pressure in the rad and it is staying in the 210 range. I have to see if I can find a way to get to the parts store to get a pressure gauge. The closest is 25 miles away. A little to far to walk. :-)

rdr8887

I would do a compression test and a coolant pressure test at the same time. Maybe even a fuel pressure test. Rent them all and knock them out at the same time.

RTorrez1

Just a quick update.
I found a new tps and iac and all my tune up parts that I had thought I lost. Put every thing on including a full tune up with no help with the rough idle. I had to give up for the day. Tomorrow I'm starting to check out all of the electrical wiring. Thank for the replies so far. I hope I can get some more from other. Also, I will be trying to get a ride into town to get the pressure gauges to do the other test that were suggested

RTorrez1

I think I have narrowed it down. It seems that #3 & #5 injectors are not feeding fuel they are getting the electrical signal but not injecting fuel. I've pulled the connection for all the injectors one at a time while running and 3 & 5 are only ones that made no difference in performance. So, do you guys think I am on the right track?
One other thing is there any special way to get the injectors out? I did try but they won't come out and I don't want to force it and snap something.

dans98xj

It looks like you are going in the right direction. The best way to remove the fuel rail is to pull it but to also wiggle it slightly as you are pulling. the best way to drain the rail is to pull the fuel pump relay and start the jeep and it will run its self out of gas. This would be a good time to upgrade to injectors especially if they are starting to give you a problem.