new plugs, wires, and backfires

[mvusse]

That many miles, it's also quite possible the timing sprockets are worn and the chain skipped a few teeth.

[carnuck]

Double check by switching #2 AND #3 at the cap and see if it runs better.

[txjeeptx]

You'll see the condition of the plugs when you do the leakdown test, but it sounds like you might have "seafoamed" carbon from the valves into fouling a plug or two.

 

Also, too much seafoam in the tank could be a problem, if that's what you did.

 

I can't believe it, the picture from the manual. Trash it. How'd that go to print?

[raviolli]

the plugs are brand new...i replaced them because it was running rough/missing and its still the same (after getting the order correct). the tank was near full when i seafoamed. i used 1/3 in the booster vacuum line (slowly) with the engine running, shut 'er off, then 1/3 in the oil filler, and 1/3 in the tank. waited 5 min, started and ran for a while. idr how long, but i ran for a while, then drove around the neighborhood a lil. there wasnt even that much smoke to be honest. hardly enough to see which i thought was kinda odd

 

that book will be trashed. i have no idea why its like that. the entire page is F'ed up...2.8l saying 1-2-3-4-5-6.....i think the 4.0 said the same in the picture, but had the right order printed. i really don't remember. but i don't trust one word of that book...it will be burned. even on the cover, it says comanche, cherokee, and wagoneer, but there's a picture of a grand cherokee on it :hmm:

 

carnuck, its up on jackstands right now as i am raplacing the booster, mast. cyl., rotors, and calipsers (+ bearings obviously) so i don't really trust the vibration of a misfire at the moment. i might try that another time but once I'm done with the braking system, ill be checking timing and whatnot so we shall see

[mvusse]

the plugs are brand new...i replaced them because it was running rough/missing and its still the same (after getting the order correct). the tank was near full when i seafoamed. i used 1/3 in the booster vacuum line (slowly) with the engine running, shut 'er off, then 1/3 in the oil filler, and 1/3 in the tank. waited 5 min, started and ran for a while. idr how long, but i ran for a while, then drove around the neighborhood a lil. there wasnt even that much smoke to be honest. hardly enough to see which i thought was kinda odd

 

that book will be trashed. i have no idea why its like that. the entire page is F'ed up...2.8l saying 1-2-3-4-5-6.....i think the 4.0 said the same in the picture, but had the right order printed. i really don't remember. but i don't trust one word of that book...it will be burned. even on the cover, it says comanche, cherokee, and wagoneer, but there's a picture of a grand cherokee on it :hmm:

 

carnuck, its up on jackstands right now as i am raplacing the booster, mast. cyl., rotors, and calipsers (+ bearings obviously) so i don't really trust the vibration of a misfire at the moment. i might try that another time but once I'm done with the braking system, ill be checking timing and whatnot so we shall see

 

How many miles are on your O2 sensor?

[raviolli]

Not a clue. Like I said I have very little info on this trucks past. I've had it a little over a year now but haven't been driving it.

HOWEVER!

I have just located a butt-load of parts so I'm going through with a major swap. We can now put an end to this post! I appreciate all the responses, you guys are very helpful and I know ill have questions again soon, as I will be swapping to a 4.0L and 4x4. Also going to add 2" more lift as long as the axles are out

 

My 2.5 no longer matters!!! :yes: