2001 TJ 4.0 rough idle and misfire

Rjhorsley22

New Member
Joined
Mar 7, 2023
Messages
8
Location
Florida
Hello. I’m hoping y’all can help me out. My 2001 TJ just started idling rough this morning and misfiring. The engine starts right up by feels like it is missing a cylinder. When test driving it feels underpowered and slow acceleration. I had multiple misfire codes and ignition coil B code. I replaced the spark plugs and ignition coil pack. Problem persisted. I then did some research and ended up replacing the camshaft position sensor, crankshaft position sensor, and throttle body position sensor. Problem persists. Any advice or where to go next? Should I be looking at injectors next?
 
Codes this morning. New ignition coil pack and plugs but cylinder 2 and 5 misfire. Leads me to believe power to coil pack for 2 and 5.

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To be honest you replaced a lot of parts and it seems like you are getting new codes. Let’s start back at the basics. Did you put a dual tipped iridium or platinum plug in your TJ? The 2000+ 4.0s are pretty picky.
 
To be honest you replaced a lot of parts and it seems like you are getting new codes. Let’s start back at the basics. Did you put a dual tipped iridium or platinum plug in your TJ? The 2000+ 4.0s are pretty picky.

I just replaced plugs with auto light xp985 iridium. Problem still persists.
 
when replacing the plugs, do any of you hose the ignition rail down with electrical degreaser before you start?? Im thinking of replacing my plugs *just because*
I have no idea how long those plugs have been in my 2000 TJ with 97K miles. I have never replaced spark plugs that had an ignition rail. But I don't want shit falling into the spark plug holes either.
and what spark plugs are you people using?? Champion, NGK, Autolite?