I would almost bet money its your crankshaft position sensor (didn't see you had replaced it?)......really common problem with these 99's.....especially if you live somewhere on the coast or where they salt the roads.....

and yes, my truck (although a standard) was doing the exact same thing and the crankshaft position sensor fixed it, runs like a champ (well, as good as any dodge does :-)

 

around 50 bucks for the sensor, two bolts (sensor is passenger side next to firewall near flywheel) and one connection, which was right next to my distributor....

99 dodge 4X4 3.9L is what I'm driving, couldn't imagine the V8's are too different....

 

I was pretty sure that crank shaft sensor might be bad, but was unable to get to it. Now I am throwing the O2 code and it makes me think it's something else. Do I have to take the plastic piece out of the passenger side wheel well to access the crank sensor? I couldn't get it off.

 

I didn't take it off....the book also sez to remove the passenger tire....I didn't do that either....granted I had to crawl underneath there and pretend I had dainty tiny hands to get in there and change it, but it only took a few minutes....having someone top-side to feed it down to you helps, or I would suggest plugging the new one in on the topside and then feeding it down and then crawl under and switch the old one and put the new one on at the same time, saves a few steps....

it really wasn't that big of a deal, and I should have listened to advice from my buddies and especially the folks on this board that told me what it was right off the bat and I chased a bunch of other "possibilities" around before finally breaking down and buying the part and changing it out....

I'll dig out the thread I started on here....

 

Thanks man! I heading to work now, but I get updates on my phone. Hope this is it!

 

I read about something like this happening with a Neon, I think the problem was a camshaft position sensor or crankshaft position sensor. Also check the throttle Position sensor, if any of these are getting wet or making contact with something it may make your truck do wacky things. Maybe once your truck worms up something is expanding just a but causing a sensor to touch something it normally wouldn't, maybe a wire is coming loose, maybe because of a bad sadder or something.

See the seventh post from the top, it's not the same but its kind of similar:
https://dodgeforum.com/forum/1st-gen...locations.html

 

A good friend of mine replaced my coolant temp sensor in my truck tonight while I am at work. I will see if it fixed the problem in a couple of hours. How do I get the black plastic cover off inside of the wheel well? I will change my crankshaft sensor this weekend if needed, just can't get to it. I tried pushing the center of the little plastic rivots in and they wouldn't move.

 

it turned out to be my coolant temp sensor! Thank you to everyone that suggested it! Hard to believe that a $13 sensor can destroy your truck like that.

 

thanks for posting up the results.....hope this will help someone with a similar problem....
dood...

 

well it seems that I got lucky the night that it ran good...it is back to running like crap. Just replaced the upstream O2 sensor and removed the cat converter incase it was clogged. Didn't help at all. Now it sounds like crap and runs like crap. I give up