2002 TJ 4.0
I recently had a new cam sensor and new crank sensor installed (both are MOPAR sensors) to try and correct a CEL (I was getting misfire codes across the board (300, 301, 302, 303, 304, & 305) but I was certainly not feeling any misfires - the TJ drove great.
The new sensors seemed to mostly correct the issue. After the new sensors were installed the only code the reader was picking up was 303 (misfire in cylinder 3).
After the new sensors the TJ drove strong but was having a somewhat rough and random shake when it was at idle. I put in new Autolite APP985 spark plugs per this forum's recommendation and that really helped. I'm still feeling a random shake at idle but it is a lot less pronounced.
My question is this: because the codes were cleared when the sensors were installed I am dreading that once the drive cycle is complete the CEL is going to come back - is this a correct assumption? If so, how long does it take to complete a drive cycle?
My follow up question is: could my ignition coil be the culprit of the rough idle / misfire? The previous owner must have had some issues with it because an aftermarket is currently installed (I'm pretty sure it's this one). I have read that if the misfire is only in cylinder 3 that it's probably not the ignition coil but I'm kind of at a loss as to what it might be if that is not the issue....
Some other info that might be helpful to the experts:
- I had my mechanic take a look at the ignition coil and he said the firing order is correct but also said the aftermarket parts can be problematic
- Mechanic also did a compression test on cylinder 3 and said it looked good - he sent me a picture of it reading just over 130
- I installed the heat shield around the number 3 fuel injector per the TSB
Any help is appreciated - this forum has been insanely helpful in my brief but problem-filled TJ ownership period
I recently had a new cam sensor and new crank sensor installed (both are MOPAR sensors) to try and correct a CEL (I was getting misfire codes across the board (300, 301, 302, 303, 304, & 305) but I was certainly not feeling any misfires - the TJ drove great.
The new sensors seemed to mostly correct the issue. After the new sensors were installed the only code the reader was picking up was 303 (misfire in cylinder 3).
After the new sensors the TJ drove strong but was having a somewhat rough and random shake when it was at idle. I put in new Autolite APP985 spark plugs per this forum's recommendation and that really helped. I'm still feeling a random shake at idle but it is a lot less pronounced.
My question is this: because the codes were cleared when the sensors were installed I am dreading that once the drive cycle is complete the CEL is going to come back - is this a correct assumption? If so, how long does it take to complete a drive cycle?
My follow up question is: could my ignition coil be the culprit of the rough idle / misfire? The previous owner must have had some issues with it because an aftermarket is currently installed (I'm pretty sure it's this one). I have read that if the misfire is only in cylinder 3 that it's probably not the ignition coil but I'm kind of at a loss as to what it might be if that is not the issue....
Some other info that might be helpful to the experts:
- I had my mechanic take a look at the ignition coil and he said the firing order is correct but also said the aftermarket parts can be problematic
- Mechanic also did a compression test on cylinder 3 and said it looked good - he sent me a picture of it reading just over 130
- I installed the heat shield around the number 3 fuel injector per the TSB
Any help is appreciated - this forum has been insanely helpful in my brief but problem-filled TJ ownership period
