bighornjd

Quick history lesson:
Bought an '89 Cherokee over a year ago that had an intermiitent no start problem. Finally got it on the road recently and intermittent problem became flat out no start. Period.
Replaced crank position sensor. Started and ran fine for several weeks, except it idled REALLY rough until warmed up then was fine. Third tank of gas since this started, started coughing and sputtering one day and was VERY hard to start a few times. Seemed worse when wet or rainy. Replaced distributor cap and rotor and it was fine for a short time then started acting up again. Thought there might be water/condensation in tank from sitting so long.
Added HEET (drygas) to tank, no more problems except rough idle when cold. Ran tank low then filled up with fresh 89 octane with another bottle of HEET and Injector cleaner added. Replaced fuel filter and removed /cleaned Idle Air Controller. This thing ran picture perfect after that for the past couple hundred miles. Idles smoothed and hasn't so much as hiccuped. Added more HEET to last tank for good measure.

Now fast forward to today, just as i'm thinking its reliable enough to make the drive to my parents house for Christmas tomorrow, coming up a long steep hill by my house it dies. No cough no sputter just flat out dies as I crest the hill and approach a curve with no power steering and not much for brakes. Bump it to neutral and restarted fine while coasting except its idling real high at half throttle or more so i don't want to dump it back in gear. I stopped and shut it off. It restarted twice but was still idling high, on the third try it just cranked and cranked, no start. Waited a minute, tried again, it started and was idling high then went down to normal idle after 15-20 seconds. I threw it in gear and it came the last mile or two to the house and ran great.

Now I can't trust it again and don't know what the hell is going on. What do you experienced folks think is the problem now? I'm getting tired of throwing time money and parts at this thing. It's runs like a dream when its running right - ha.

BTW its an 89 Cherokee with the 4.0L and auto, 176,000 miles.

Thoughts? thanks.

bighornjd

After more reading I'm thinking maybe TPS but at this point I honestly have no clue...

ETA: Forgot to mention before that I replaced the ignition coil at the very beginning of this mess when it wouldn't start - before the CPS.

Abovetimberline

It could be the tps,they will cause the high idle at startup,but the rough idle I think is your iac,it can also cause the high idle. It can be taken off and cleaned,with throttle body cleaner and an old tooth brush,make sure the o-ring is in good shape,if the iac is not operating right it will act like a vacuum leak.

RevZeroX

MAP sensor?? just a random thought.. Maybe fuel pump? A new tps ran me about 45 bucks just a few days ago. I got a 89 with 195k on it.

sorry I cant be of any more help.. just bouncing ideas on your problem.

bighornjd

After doing some reading on here I have already taken the IAC off and cleaned it. That did take care of the rough idle. I did that last week and it has idled smooth as silk ever since. Maybe I should change that anyway and the tps since they don't sound too expensive.

SeriousOffroad

Check you PM inbox.