My 2003 Jeep Liberty started shaking and engine light turned on in December. The code was cylinder #3 misfire. My husband (mechanic) replaced the spark plugs, and the misfire continued. He changed the coil and the misfire continued.
We took it to the shop (not a Jeep dealership) and they tried switching the coils around and they said the codes kept changing. It would go from cylinder #3 misfire to other cylinder misfires, not coorelating with the coil that they had moved. (It would misfire a couple different random cylinders at the same time, with no pattern.) They gave up and said to take it to the Jeep dealership because they thought it might be a computer issue.
They cleared the codes, and my Liberty was running great for a few months so I didn't take it to the Jeep dealership. Now the misfire (and engine light) are back! The weird thing is that it will do it constantly while I'm driving, but if I pull over, turn the Liberty off, then start it up again, it will run just fine, without misfiring!
I'd appreciate any advice! I don't want to take it to the dealership and spend a fortune!
No, the code didn't follow the coil when it was put in a different spot. (They would have recognized that...) When they moved the coil to a different spot, it would misfire two different cylinders (like #3 and #5, #1 and #6, etc) There wasn't any kind of pattern, it was just random misfires.
I had the same problem for 2 months until yesterday... Mine was slightly different, the check engine light never came on... You've already changed plugs and wires (this solved the problem for me) AND switched the coils around... So that leaves possibly 2 more culprits-throttle sensor & crankshaft sensor (which would have been my next course of action if the new spark plugs and wires did not correct the problem). Hope this helps.
I just read your post from 2008 re your Jeep misfiring. You described exactly what mine has been doing off and on for a year now. I replaced the Crank Sensor, the coil, the plugs, the MAP sensor, and now the mechanics are completely baffled. Did you ever find your problem? If so, please let me know.
My 2002 Libby started doing this earlier this week, the #6 cylinder misfiring.
Started it up Monday morning then went downtown to stop a couple of places, it was running just fine. First stop was at Staple's, then when I came out and started my jeep, it felt like it was idling kinda rough. So I revved it some to try and clear what ever the problem was and headed to the supermarket for a bit. It ran fine except when the RPM's got were low, then it'd be rough again.
When I came out of the supermarket, after I started it there was the same problem. But when I went to backup, the roughness made it feel almost as if it was lurching a bit as if the four wheel drive was engaged and fighting rough ground. Was kinda worried that the jeep would die there in the parking lot.
By the time I got home, it seemed to be running normally again. Didn't drive it again until this afternoon and the roughness was kinda worse and you could hear it the way the engine was running. I decided right then to bring it straight to the garage at the end of our street. They thought it might be the EGR valve or something else along those lines.
They called me back this evening saying my jeep was ready. They did a diagnostic on it and they checked the wires, coil, pulled and cleaned the plugs. They say it's running fine now, but they said there was a funny odor like cat urine in the cylinder that was misfiring when they pulled the plugs.
I haven't had a chance to drive it yet, but seeing as they had an opening tomorrow, I scheduled it to have an oil change and to have them check the entire vehicle out to see if it needs to have anything done, including the suspension.
I just hope the misfiring issue doesn't return and if it does, I hope that it doesn't need a valve job. I was hoping to use that money for some other stuff that needs doing this year and I'm kinda hoping to be able to install an OME HD lift kit if we have enough money left.
Then again, it probably didn't help matters that my jeep sat most of this winter and in the last six months, I put only 1000 miles on it.
[i]- Excuse the writing, I've got a Dyslexic Keyboard[/i]
It's amazing that if you pamper your car too much or dont drive it enough it can actually be detrimental. I think my problem stemmed from my wife not driving the truck enough and taking too short of trips and not allowing the engine to ever reach a hot enough temperature especially during the winter.
I got the relay from parts plus about 8 dollars. As a test you can swap the ASD anad the blower relays in the fuse box. They are both the same type relay sitting next to each other in the fuse box next to the battery.
if anyone can help. i have a 02 jeep liberty 4wd limited.. my engine light came on n i had it checked, they said it was tps sensor, i change it but engine still sounds like misfiring or spottering...i change fuel filter addedd fuel injection cleaner and changed spark pluggs, but still the same. can anyone help? i dont know what 2 do no more...