krew

i was picking up a buddy and while i was waiting my jeeep started to run like **** i was able to limp it home but trying to figure out what was wrong with it i found that i was only run on the front 3 cylinder when i puller the plugs the front 3 were black and the back 3 were white and wet i have tryed just about everything cant figure it out



any one got any ideas????

belvedere

Like what?

krew

changing injectors, plugs, wires, cap, cam sensor, check feul pressure changed ecm, all the sensors on the intake

belvedere

Let's slow down and troubleshoot instead of shotgunning it. It is a strange symptom, indeed, but you still need to approach it systematically.

First step: are you missing spark or fuel on cyls 4-6? Have you tested compression?

deekay911

you have distirbutor or coil packs?

tiegs89xj

If they're wet I would check your coolant. If theres water in your cylinders that would cause them not to fire

krew

yes its getting spark cuz i got poked lol and no that the onlt thing i havent done and its a distirbutor

belvedere

I guess my next step would be to check compression. Maybe someone else has seen this symptom before, and has another idea, but that's what I'd do.

Willys55

I agree, check compression and stop throwing parts at it like a Zoo Keeper feeding the Lions.

cruiser54

LOL. BTW, what the heck are we working on?

BTW, a huge intake leak could be an issue.

CCKen

Looks like he/she has a 1999 Cherokee with a 4.0 motor....and a fat wallet.

krew

its a he and that ones of my other ones lol and the one i am haveing issues with is a 98 classic with the 4.0l and my buddys got the same one so we have been swapping parts to see if thats the issue

krew

just got done doing a compression test and heres the numbers 1-130 2-140 3-125 4-130 5-140 6-0

CCKen

Geeez, that motor sounds like a jewel.

Check to see if there's a piston in #6.

Remove the fuel pump relay, disconnect the coil primary connector, remove #6 sparkplug, Have someone crank the engine over while you hold your finger over #6 spark plug hole. See if you get any pressure to build up whatsoever (is that a word?).

Replace the spark plug, leave the relay out and coil disconnected. Remove the TB intake tube. Hold the throttle plate open and have someone crank the engine, listen for air escaping through the TB. If it does, the intake valve has a problem. If not go to the tail pipe and listen there while it's being cranked. Same story, if you can hear air escaping through the tail pipe it's a bad exhaust valve. If okay, listen at the oil filler on the valve cover and/or oil dipstick tube (with a length of hose at the opening). Air escaping would indicate a bad piston or rings are laying in the oil pan.

Option would be to do a compression loss test on #6 using 90 psi air and do the listening things. Edit: And do a compression loss check on #5 with #6 plug removed and see if the pressure in 5 bleeds accross to 6.

krew

ok ill try that stuff but that dosent solve the issues of not firing on 4 -6 i can seeing bleeding from 5 to 6 but where would the cylinder 4 come into play?