I just got my xj a couple months ago, and the check engine light came on for the 2, 3, and 5th cylinder misfiring. So i just changed the plugs today, triple checked everything, made sure all of them are at .035. Then after i start it up, its misfiring way worse, barely drivable. The check engine light started blinking and then i checked everything again. still looks fine.
Anyone have any clue on what i did wrong, or what i can do?
thanks a lot

 

Bumpp

 

did you mix up the wires

 

firing order

 

It's not the firing order, I have the spark plug rail, no distributor.

 

Posting the year/engine would have eliminated the confusion on wires/coil rail.

Keep concentrating on those codes. Pull the stored codes again. Did you clear them the last time they were read?

Best to post the exact code numbers here for comment. With OBD, the devil is in the details.

You could have a fuel delivery problem, not an electrical problem. Checking fuel pressure with a gauge would make some sense, but follow the lead of the codes. Is there a P0300 for random misfire?

Know that a flashing check engine light indicates a SERIOUS misfire, which if left long enough, will destroy your catalytic converter.

You need to resolve this ASAP.

 

all info would of been helpfull id say the problems in that rail then

 

Sorry about that, its an 01 Cherokee. I used borsch platinum plugs, someone just told me you can't really run platinums in the 4.0s so I'm gonna use champions and hope that works.

 

You can certainly try it, but I don't think it is going to resolve your issue.

If it still misfires, give a fresh read to the codes and post them here for comment.

Don't drive this for more than a test drive until this is resolved. Or your cat will toast.

 

The champion plugs worked. The guy at advanced auto said they were having a lot of complaints about all the Bosch platinums lately. Atleast they refunded me the 19 dollars for those plugs lol.
I appreciate all the help, thanks guys.

 

Wow...that is interesting that the Bosch plugs would create a serious misfire.

I am partial to Champions as are most with the XJ, but I wouldn't have thought that
the Bosch plugs would create that symptom.

Very interesting.....