TJ with acceleration issues after sitting 3 years

I filled up this morning with Chevron mid grade and a bottle of Lucas fuel injector cleaner and my TJ ran great but I still have that “tapping” or whatever you want to call it. Could it be something g vibrating under the Jeep?
 
Well, that didn’t last long. 15 miles in and the hesitation came back at 20, 40 and 60 mph. This time it threw P0300, P0301 and P0305. All are misfire codes. I don’t know where to begin with this thing.
 
BDub7473 said:
Well, that didn’t last long. 15 miles in and the hesitation came back at 20, 40 and 60 mph. This time it threw P0300, P0301 and P0305. All are misfire codes. I don’t know where to begin with this thing.
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for the 301 & 305, I would approach it scientifically. Clear the codes and move the spark plugs from 1 & 5 to two different cylinders and see if the misfire follows the plugs. If the codes come back in the same place, you can then move the injectors and run the same test.
 
hear said:
for the 301 & 305, I would approach it scientifically. Clear the codes and move the spark plugs from 1 & 5 to two different cylinders and see if the misfire follows the plugs. If the codes come back in the same place, you can then move the injectors and run the same test.
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Thanks for this advice. This approach makes a lot of sense. I just removed the plugs and here is a pic aft right at 200 miles since they were replaced. I will clean the up and then install them in different cylinders. I will report back soon with my findings. In case it makes any difference these are Autolite Iridium XP985 plugs.

IMG_0721.jpeg
 
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Well, moving the plugs around has corrected all my problems. I did replace the plug on the #5 cylinder due to it had some scarring on the threads. It ran awesome for about 29 miles and then I parked it because I needed to get some stuff done. I wonder if there was an issue with that plug in the #5 cylinder? I will advise over the next few days if it’s still good.

Thank you all for the support!
 
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BDub7473 said:
Well, moving the plugs around has corrected all my problems. I did replace the plug on the #5 cylinder due to it had some scarring on the threads. It ran awesome for about 29 miles and then I parked it because I needed to get some stuff done. I wonder if there was an issue with that plug in the #5 cylinder? I will advise over the next few days if it’s still good.

Thank you all for the support!
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It's very possible that it was an intermittent misfire (it doesn't take but something like 2 misfires within a certain # of cycles to throw the code) and it simply hasn't returned yet. I've had a P0301 in my '02 for a year. It cleared on it's own over the winter, and then for no good reason it came back last week.

So I wouldn't count your chickens just yet.
 
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