Rough Idle, Hard Start

Okay, I have a '92 4.0. I replaced the motor 15,000 miles ago. I replaced every sensor, the entire fuel system, and all of the ignition system as well.

The problem is, the Jeep wont start unless the throtle is applied, and when it starts the idle is really rough, blows black smoke and smells like it is running rich. Then today, sitting at a stop light I turned on the AC, the idle fluctuated (in the low 200-300 range), then died. WTF!!!

I had a similar problem with my 96 XJ, I replaced one of the relays and it ran fine. It was the ASD or ADS relay, something like that... it was a $15 part at the store.

Good luck, mine drove me nuts as well.

-Jamie

I'll give that a try. Thanks for the quick response!!

Replaced the relay this morning. Didn't help. Any other suggestions? This is driving me nuck'n futs!