Having trouble with stalling....Main symptom is if i'm stopped with foot on brake, car will continue to idle, although at times erratically, but as soon as i barely touch the gas pedal, the vehicle will stall and the engine will shut off.

It doesn't take much to restart it, so there haven't been any issues with crank. But in order to safely pull out in front of traffic (coming from a safe distance) i have to mash the pedal hard just to feel secure enough that i don't get broad sided. I've read all the usual tips...and i'm not going down fuel related issues at this point (pump, pressure etc). Nor am i thinking it is ignition related.

I'm leaning more towards air/gas mixture and the related sensors sending info to the ecm...such as tps, aic, map etc.

What i haven't seen a lot or any at all is the suggestion that the EGR valve could be a culprit.

Do these rarely go bad in the 4.0?

I had a saturn that needed the egr cleaned often, or it would run like sht.

So far i have NOT replaced any parts, and there are no codes present.

Just now beginning the troubleshooting process.

1994 jeep cherokee country 260,000+ K

*** note: the symptoms will continue while driving. while at cruising speeds the rpms will sporadically drop enough to cause the transmission to shift down in a lower gear.

 

i think i've found an answer to my question.

EGR valves NEVER go bad in the 4.0.

unless it is the 1987-1990 renix motor.

 

If you havent already, check your vacuum lines and hoses, and fuel pressure.

 

yes, for sure. my vacuum lines are patched in places with tape.

this is an educational request, but how does a leak cause so much strife in the engine!

i've read a leak will cause high idle, but my symptom seems to be the opposite.

 

Clarification. Only 87 to 90 HAD EGR valves and they rarely fail.
You must get the vacuum lines up to snuff before anything else. This should help.

http://cruiser54.com/?p=121

 

thanks for the tip and link for the harness.

seems like it is split for those advising to use the harness, or generic hoses.

in either case, i should do a leak test first before moving forward.

 

well it went bad on my 96 carried on like the tps was going bad

 

I would check your IAC idle air controller my 87/89 had exactly the same problem. It ran pretty good but as soon as I lightly touched the throttle it would stumble and fall on it's face. You can pull the IAC and plug it in to the harness. Cycle the key on and off (don't start it) watch the tip of the IAC, it should move in or out a little (like an 1/8th inchish). I changed it and it's back to running like a top.
By the way my EGR is currently bad and I'm having a hard time finding a new one, but she still runs great.