Drove to work this morning, and it started.
About 10 minutes into my drive, I stopped and got some gas and went on my way.

When I got off the freeway, it started bucking. I came to a stop light, and very subtly, i noticed it was bucking. The rpms were jumping up and down very slightly. I pulled over and let it idle in park, and it wasn't doing it. Pulled away, came to a stop, and it started again. I could also feel it doing it while traveling at about 50-55 mph.

I haven't gone back out and started it back up again yet. No weird noises.

I usually park it inside, but not last night... But the night before, i had to park it outside and it's been below zero here. It hesitated to start after being outside over night.

It has just under 3000 miles on the rebuilt motor.

Recently had the "brains" of my alarm/auto start replaced. That was a couple weeks ago.

 

Double check all of your transmission to engine mounting bolts. If they are loose your CPS will not read properly.

Been there, done that.

 

when you had the engine rebuilt, did that include new plugs/wires/distributor?

SeriousOffroad's suggestion sounds good too especially after the engine was out.

 

Motor rebuild included all of the above and a new rad, water pump, and thermostat as well.

I will be taking it back to the shop to have it looked at, but first I was thinking of trying some dry gas if it's still doing it when i leave work. Bad gas maybe?

 

Try adding some techron or Lucas fuel treatment to your gas. I'm thinking possibly bad gas

 

Well, on my way out of work... I auto started it. As i walked out to the Jeep, i could hear it still sputtering. Took it to auto zone, as the CEL had now come on. Cylinder six misfire.

It had stopped misfiring as i pulled up to AZ, so i figured I'd drive it the twenty minutes to my mechanic.
Got a few miles up the road, and it got so bad that i couldn't accelerate past 50 mph without feeling like i was trying to turn the truck with 4 wheel engaged on dry pavement. It was bucking like a damn bronco.

So, now it's here at the shop that rebuilt the motor, and their gonna get a look at it tomorrow. Had it towed here. Thank God for AAA.

 

definitely sounds like an ignition system problem somewhere! good luck! :-)

 

Coil pack went bad apparently. Off to the u-pull later today...

 

Some stupid guy at the u-pull decided to "help" remove the only coil pack in the junk yard, and broke the damn thing.

Found a used one for $35 though... Hopefully it works. A new one at auto zone is $104 that I don't have right now.

 

Where are you located? I could get you one for a lot cheaper. If you are you using the the used one, it should be temporary till you get a new one

 

Swapped it out... Not the problem. Mechanic is full of it. It was gonna be a temp fix, but seeing as how it's so obviously not the problem... I'm back at square one. Made a new post with updates, and new questions.

https://www.cherokeeforum.com/f2/200...8/#post2268189