Running rough and stalling at low rpm

[BPB]

:dunce: So I left my hood open for a day or so in the rain. durring this time i replaced my dash wiring harness. now today I drove it to school (15 minits or so) it died at a stop sign, it died as i got off the freeway. It is running rough. Also i noticed a little black smoke, so i put my hand over the exaust and there were some little black spots. I have noticed a lack of power lately, I thought that It may be because of my cracked exaust manifold. I have an xj that is identical year (1990) motor (4.0) and tranny (ax-15). I am thinking about pulling the throttle body off and replacing that. What else should i consider?

[BPB]

Also my temp guage that wasn't working before the wiring swap still isn't working...

[mvusse]

Are you firing on all cylinders? Could be moisture in the distributor cap.

[FxRacing282]

sounds like you have a A/F problem. check to make sure you have the TPS hooked up properly, the MAP sensor hooked up properly and the O2 sensor wired up and hooked up properly. black smoke means this. too much gas OR too little O2. they go hand in hand. you could try swapping throttle bodys. but id check connections and double check and tripple check and have your mechanic friends with some brains, (not the dumb ones) take a look.

[BPB]

throttle body did it, the old one was gummed up, I have more power than i have had in a year or so. I am gonna take the intake manifold off my xj and sent it with my buddy to work to have him run it through his works parts washer, along with my old throttle body.

[Eagle]

Make certain you remove the throttle position sensor. They don't like to get wet -- which is why yours started running funny after you left the hood open for awhile. I had a mental lapse and left the hood up overnight a couple of weeks ago after doing some minor work. Naturally it rained that night (thankfully not too hard), and the thing ran terrible for most of the next day. Didn't want to idle under 3000 RPM.

 

Then I parked it for a few hours after it had gotten fully warmed up, and I guess the heat baked off whatever moisture had gotten into it. It's been fine ever since.