93 Cherokee tries to stall, but never stalls out completey.

[Scott814]

93 Cherokee 4.0, auto, a/c, 131,000 miles.

2 issues really. First, and not that big of a deal. When a/c on and you blip throttle, it will idle down to almost 200 rpm, a/c compressor will cut-out and idle returns to normal. Does this mostly when cold, rarely when warm.

Second and most frustrating. Near stall issue intermittent problem only when in gear both at idle and when moving. Never if only in park and idling. It feels like it is trying to cut-out, but never really does. Seems to be worse when humidity is higher, rarely ever does it on a very clear low humidity day. Rarely does it when the vehicle has been driven for a while and is well warmed up, but it sometimes it will. Had a 91 XJ that stalled when coming to a stop and fixed that with regular cleaning of the TB. Have done same on this to no avail. New plugs, wires, dc, rotor, af. I'm the second owner, and have only had it since 118k. Problem has been with me from 2nd month I've owned it and shops can't find the problem. No codes from computer. Have read some of the posts and will try some of the easy things like checking wires, fuses, etc.

No starting problems, and it never cuts out completely. Has only stalled out once after startup in 12k miles. I don't know how old the fuel filter is. Haven't changed that yet.

Any suggestions would be appreciated.
thanks..

[Cam7]

Sounds like it could be your IAC motor. Also do a few checks as what your voltage is when you turn on the AC and if you geta drop. Also check the fuel pressure. My !st guess is the IAC.

[Scott814]

So far: Cleaned tb and iac and housing where it is installed. iac very dirty, full of carbon. Found fuel pump ballast resistor cracked and seperated lengthwise, replaced that. Positive battery terminal was so loose you could pull right off. Cleaned terminal and post and tightened properly. Seems to idle smoother, and so far can't get the idle to fluctuate down like before. Need to drive for a while to validate results. Hoses, connections, grounding, external relays and fuses look ok. One step at a time!! thanks..