Our 94 started out acting up while underway with a lurching fit that would eventually clear up. Now it will lurch and then stall or stall out of the blue.

Is this likely fuel delivery, ignition or electronic in nature usually? Where to start? Trouble shooting links will be put to good use.

I am able to do the work. Have DMM and anything else I need for the most part...

Brent

 

Found a fuel filter in need of changing but not my problem with this vehicle... Still need help with this...

Brent

 

I would start out by testing all its normal vital sighns Fuel and Spark, I would also do a compression test and get back to us with all the results and current symtoms.

 

My XJ would stall out of the blue as well. Come to find out it was a battery cable issue. Check your cables as well. My positive one was melted though and was touchin the negitive one causing shorts and the stalls

 

Haven't done a full trouble shoot but it did fail at store...
My findings... Loosen fuel line at rail... GREAT pressure.
Press valve stem on rail and find equally great pressure.

Remove a plug wire from plug and find no spark... A couple attempts had it fire and die... Really feels like fuel starvation as it dies but I guess at lower rpm's it would be hard to tell what cut out.

Prelim on 12v at battery seemed good but not complete inspection. Will check dizzy cap and rotor first thing in AM... Is there a bonafide diagnostic test I can do on the coil? Volts? Ohms? Which poles to test on? I am fully ept to undertake this and have a digi multi meter in hand at the ready...

TIA,
Brent

 

There is a resistance test. Not sure what proper resistance is. If you Google it you'll probably find it. At least make sure resistance between pos and neg isn't infinite.

 

There is a gang of wires that comes up in front of the manifolds and around the heat shield then back to the injectors. Mine grounded, a little, sometimes on the sharp edge of that shield. Sometimes after it expanded while sitting with the engine hot. Took only a year and a half of bucking and 6 inches of electrical tape to fix it.

 

Plugs were near 90 thou so dropped a set of bosch platinum in.
Old coil had different ohms than new one and a few detectable cracks.
Dizzy cap and button new.

Haven't put enuff miles to be sure no sensors are trippin' out.

Thanks for the help... Will be back next time...
Bookmarked for old timers disease.
Brent

 

Doubt it's causing any of the problems, but I remember reading that the 4.0's don't like platinum plugs. Champion copper truck plugs are what's recommended most

 

Old plugs were AC Delco... I prefer NGK ND or Bosch.

Brent

 

Well that wasn't the fix...
What are the diagnostic tests for the sensors.
Is there an "ignition module" or other type device that commonly suffers failure when hot but fine when cold? Do the sensors also suffer the same symptoms?

Never was a fan of Mopar electrical and electronics for this reason.

Brent