2000 XJ strange misfire. HELP!!!!
i never got that i got a cyl 1 misfire code and evap from fuel trim
Banned
Joined: Feb 2014
Posts: 2,379
Likes: 18
From: Florida
Year: 2000
Model: Cherokee(XJ)
Engine: Golen 4.6L
That's one of the things that frustrates me about OBDII and these '00-'01 computers in particular. OBD is supposed to stand for On-Board Diagnostics. Yet instead of diagnosing anything, it gives you a misfire code for a couple of dozen different problems, when you can usually tell from the way it's running that it's misfiring. Duh. Tell me why it's misfiring, you useless pile of...
That's one of the things that frustrates me about OBDII and these '00-'01 computers in particular. OBD is supposed to stand for On-Board Diagnostics. Yet instead of diagnosing anything, it gives you a misfire code for a couple of dozen different problems, when you can usually tell from the way it's running that it's misfiring. Duh. Tell me why it's misfiring, you useless pile of...
No, I don't lick fish.



Joined: Mar 2011
Posts: 11,169
Likes: 26
From: Northern Kentucky
Year: 1999
Model: Cherokee (XJ)
Engine: 4.0
turns out it was the intermediate tube going from the fuel pump to the front of the assembly where the fuel line connects. It was too short and blew off so when the fuel pump would pump gas into the tube, it would just drain back into the tank.
p0301
i cant seem to get rid of this darn thing. i have a little new insight. if left to cool down for a few moments it will run without the severe misfire for a little bit but then it just registers again a few miles down the road.
i cant seem to get rid of this darn thing. i have a little new insight. if left to cool down for a few moments it will run without the severe misfire for a little bit but then it just registers again a few miles down the road.
Banned
Joined: Feb 2014
Posts: 2,379
Likes: 18
From: Florida
Year: 2000
Model: Cherokee(XJ)
Engine: Golen 4.6L
Have you tried everything in post #10? If you have an air compressor, I'd add a leak down test to that list to be sure you don't have a valve issue.
And don't brush off the suggestion to take a look under the valve cover. I tried everything I could think of to solve my #6 misfire except pull the valve cover off, and it turned out to be a broken spring that was pretty obvious.
So it wasn't so simple after all. Nuts.
Have you tried everything in post #10? If you have an air compressor, I'd add a leak down test to that list to be sure you don't have a valve issue.
And don't brush off the suggestion to take a look under the valve cover. I tried everything I could think of to solve my #6 misfire except pull the valve cover off, and it turned out to be a broken spring that was pretty obvious.
Have you tried everything in post #10? If you have an air compressor, I'd add a leak down test to that list to be sure you don't have a valve issue.
And don't brush off the suggestion to take a look under the valve cover. I tried everything I could think of to solve my #6 misfire except pull the valve cover off, and it turned out to be a broken spring that was pretty obvious.
CF Veteran


Joined: Mar 2015
Posts: 1,203
Likes: 155
From: Northern CT
Year: 1995
Model: Cherokee
Engine: Turbo 4.0
Your DTC is still pointing to cyl1. Cut the tape away from injector 1 pigtail and inspect for any breaks in the insulation/wire. After rewrap the wires 2 or 3 layers thick and keep them from resting on the fuel rail. It only takes 5 minutes and it's freeish.


