sounds like im dragging cylinders

[603Redneck]

hey guys, ive tried everything i can think of and I'm out of ideas. my 88 2.5 comanche is idling really rough and when you give it full throttle it completly dies, but when you let off the throttle it comes back and idles like $#!& again. i replaced cap,rotor,wires and plugs. its also got brand new alt in it. only other thing i can think of is TPS or comp. anyone got any ideas?

[BLHTAZ]

Have you had the distributor loose or out recently? There have been a couple guys around here with similar issues and it was found to be the distributor was off by one tooth in both cases.

 

You also have a timing tensioner in your engine that the 4.0L's don't have that could be gone and allowing your timing to be thrown way out of wack.

[603Redneck]

Have you had the distributor loose or out recently? There have been a couple guys around here with similar issues and it was found to be the distributor was off by one tooth in both cases.

 

You also have a timing tensioner in your engine that the 4.0L's don't have that could be gone and allowing your timing to be thrown way out of wack.

 

no i havent had the dist out or loose at all. it almost seems to run ok at around 3-4 rpms but i can tell its still not right. i thought of that tensioner but was hoping not to have to pull the cover to check it

[603Redneck]

also it did this to me before awhile back. then it was cuz the alt was junk and when i floored it, it didnt have enough voltage to open the injector up so it bogged down like it is now. but its a brand new alt and when i disconnect the batt it still runs so thats not it this time. it just started happening again, i went out wheeling and it was running perfect, went to go hook up to pull my buddy and it started doing it again.

[603Redneck]

oh, and when i replaced the old cap and rotor, the rotor had somehow chewed into the cap pretty good. that mean anything?

[Eagle]

oh, and when i replaced the old cap and rotor, the rotor had somehow chewed into the cap pretty good. that mean anything?

Ummm, yeah. It likely means that your distributor is worn out, the shaft is wobbling around, and it's not properly keeping time. Sounds like you most likely need a new (or rebuilt) distributor.

[mvusse]

X2

[BLHTAZ]

oh, and when i replaced the old cap and rotor, the rotor had somehow chewed into the cap pretty good. that mean anything?

Yep...exactly what Eagle said.

 

If you look in there now...you will probably see the same problem developing again ;) .

[603Redneck]

the shaft don't move at all, theres no play in it and the new cap and rotor look fine, no scarring or anything.

[603Redneck]

what about the TPS? i unplugged it and nothing changed, plugged it back in pushed the lever down and no change in idle. think that might be causing it?

[ejndssn]

oh, and when i replaced the old cap and rotor, the rotor had somehow chewed into the cap pretty good. that mean anything?

and it don't take much movement to comsume the inside of the cap :brows: look into getting that replaced and ensure when you do that the no. 1 piston is TDC.

[603Redneck]

ive also been told that running the comp at not the proper voltage (when my alt was bad and ran it all day on the batt till it died) it can either screw up the comp or the sensors. any thoughts on that?

[603Redneck]

well i replaced the TPS and that didnt do it, took the comp out and opened it up, dosent even look like water even got in there, its still shiny (its obviously a rebuilt) and no soot or anything. I'm lost......

[maddzz1]

Have you cleaned/tested the idle air control? If that don't do it I would start with the above suggestions: timing tensioner and distributor.

[603Redneck]

what about the tensioner on the timing belt? would that cause these symptoms? i don't want to go through the hassle of pulling the timing cover off if thats not the problem.