Hey everyone.

Well this is my first post so hopefully it goes well. lol I have been having an ongoing issue with my Cherokee the last little while. When its warm it will miss slightly, and it has some hesitation for the first km or so down the road. Once I get it up to speed is smooths out and runs fine; except for 2 times so far. Its would be idling rough and missing but when I pulled out to accelerate it wouldn't have enough power to do it and then would die and not restart. Its would have ever fire right away if I pull the intake and shoot some carb cleaner in it. After doing this 1 or 2 times and it will stay running smooth as can be like nothing happened. I do also notice that at all times if I step on the gas to the floor is has a little bog all the way through the rpm curve. Hard to explain, it goes good but if I do the same run at slightly less gas pedal it will accelerate noticeably faster. Not sure if thats related or not. This has been going on for a couple months now with no big issues other the a lid annoyance and inconvenience. Today how ever it was running a little rough like described above, but this time it kicked on the CEL.Code 43 - mis fire. Ok no sh*& its running rough, chances are its mis firring. Why only would it come on now. Any insight into any of this would be greatly appreciated. I'm sure its all related but since it only does it intermittently and never in the shop that would be great as its being pretty hard to diagnosis.


Cheers

 

I would replace the cps(crankshaft position sensor)

 

would this cause it to run bad if you shut it off for a few minutes then go to start it and it will barely run? when it does that i can smell fumes bad. i have to pump the gas to get it to clear out then its fine.

 

Your problem sounds like a fuel pump going bad

 

i had the same exact problem, its your fuel pump its not flowing enough fuel to keep up with your injectors, one way to test is start it then pop the hood and throttle the engine with your finger right at the throttle body(go fast all the way to full) if im right it will sound like it sucks alot of air and bogs then if you let off the throttle it will catch up at about half throttle, if not then it could be your crank postition sensor

 

check your cam sensor also

 

it has been doin it for about 4 or 5 months atleast. lol

 

is there anyway to test these sensors to see if there bad?

 

Thanks for the thread jack, roughridenxj... now I don't know (and I doubt if the OG poster knows) who these replies are helping, you or him (or her).

sweet96cherokee: I'm having the EXACT same problem as you've described. Not the same as what roughridenxj describes when he gives it throttle to clear out the fuel. What have you tried so far? Have you replaced the CPS yet? I regapped my plugs a little wider than .035 and it helped... a little... very little. But the problem is still there. I'd hate to buy a new CPS or CMP without knowing for sure if thats the bad part.

 

My '01 xj had ignition problems that acted exactly as you describe. I changed the plugs, coil packs and coil pack boots. It now idles smoothly and runs without misfires. Just something you might want to check out.

 

Change the fuel filter. Its only $13 and needs to be done once a year. A clogged fuel filter will cause hesitation.

 

im sure if they cared they would have said something. the quote button you click would help what post goes to who DICK i didnt know they needed someone to talk for them. sorry for thread jacking sweet96cherokee..

 

I'm having the same problem but after it stalls the first time the check engine light comes on. Also I put some gumout fuel system cleaner in it yesterday morning when I filled the tank. The problems started in the afternoon on my way home from work. Not sure if that caused problems and maybe if I just go through the gas it might clear up or what.