Help needed XJ not well

[61galwagon]

I have a 97 XJ 4lt that is having issues, was running fine then started missing and stalling i have replaced plugs, leads, dissy cap, and rotor button. I have checked fuel pressure at injector rail all good.

The engine revs at idle will jump between 1000 - 2000 rpm and just drop to around 500 rpm and the back up to 2000 rpm since replacing the above parts.

When on the road the car will drive fine and then just miss under load and then stall when stopping

The other thing that started at the same time is that the gearbox kick down wont engage don't know if the two are linked.

I have read other posts with similar issues but none have had kick down issue mentioned.

[rustynuts]

Originally Posted by 61galwagon

I have a 97 XJ 4lt that is having issues, was running fine then started missing and stalling i have replaced plugs, leads, dissy cap, and rotor button. I have checked fuel pressure at injector rail all good.

The engine revs at idle will jump between 1000 - 2000 rpm and just drop to around 500 rpm and the back up to 2000 rpm since replacing the above parts.

When on the road the car will drive fine and then just miss under load and then stall when stopping

The other thing that started at the same time is that the gearbox kick down wont engage don't know if the two are linked.

I have read other posts with similar issues but none have had kick down issue mentioned.

It's hard to diagnose cars with little information but you may have a vacume leak causing your idle air control valve to become erratic. That may cause transmission faults too.
Check and listen for any leaks around the intake manifold.
Check for fault codes too. That may narrow things down.

[rainman]

Does it run alright cold then start misbehaving when it has heated up?

[61galwagon]

It plays up hot or cold.

Sent from my D5833 using Tapatalk

[rang0]

Ive read that if the autos lockup solenoid is stuck it will stall the engine as its mechanicaly engaged. But that wouldnt make it miss i wouldnt think. What year is the 4.0? Ive also read that a gear on the cam that either runs the dizzy or crank angle sensor wears out because its plastic... not too sure about that one just some thing i read when i had the 4.0. Have you checked the compression? Pull your plugs and have a look at them. Is it a major miss? Have a look at you air flow sensor thats how it tells the computer how much fuel to deliver. It might be worth pulling all the sensors out of the manifold and cleaning them might not make a difference but atleast you could rule it out.

Sent from my SM-J100Y using Aussie Jeep Offroad mobile app

[bleetnblurt]

try the MAP sensor.

[Roler]

Welcome to the forum.
Before you will be inundated under suggestions regarding possible causes (and I'd think common causes being common: CPS, CAM, TPS, IAC, vaccuum leaks etc etc), let's try to get this clear first:

Did the symptoms (looks like you describe the enginge surging at idle) start AFTER you replaced all those parts or did you replace those parts BECAUSE you were trying to solve those symptoms (because a tune-up will not have much to do with those)?