2003 4cyl Explorer suddenly has cylinder 1 misfire

[jimborasco]

I've been trying for the last two days to figure out what the problem is with this thing. 144K. Out of the blue, started having intermittent shudder/jerk at interstate speeds after a trip of about 100 miles roundtrip. No problems on the way there, this happened on the return trip. CEL came on solid, then later started to blink.
I have no experience with onboard computers/scanners AT ALL. So, I stopped at auto zone and had them check it. They got two codes. One for MAF and another for misfire on cylinder one(1). I bought the MAF cleaner and new plugs. (I have no idea when they had last been changed and I have had this Explorer for a year and put less than 2000 miles on it). After that, still had a pretty rough idle and some jerking/missing down the road at home on test drive. Next day, I changed the plug wires and that also didn't help. CEL still blinking, btw. Tomorrow, I plan on changing the coil. Also, can/should I disconnect the battery to clear the computer?
If changing the coil doesn't work, can someone please give me some ideas as to what I should try/check next? :scratch: My wife is having surgery in a couple of days and I really would like to get this fixed before then. She'll need me and I won't be able to get back to it for a week or so and I'm trying to get it fixed before then. Any help or ideas would be greatly appreciated. Thanks for taking the time to read this.

 

[Bobmbx]

Try replacing the MAF. Sometimes cleaning it works, sometimes it doesn't.

If you can, post the codes that the shop pulled for you.

 

[jimborasco]

Thanks for the quick reply, Bobmbx. If the coil replacement tomorrow morning doesn't do it, I'll try a new MAF. I'm sorry but I don't have the codes they pulled. But I will make a mental note of any codes next time I have any trouble so that I can post them here. I didn't even think of asking for them.
I'll post back with a followup when I have one so maybe someone else will find the info useful.

 

[anthonymtz]

Thanks for the quick reply, Bobmbx. If the coil replacement tomorrow morning doesn't do it, I'll try a new MAF. I'm sorry but I don't have the codes they pulled. But I will make a mental note of any codes next time I have any trouble so that I can post them here. I didn't even think of asking for them.
I'll post back with a followup when I have one so maybe someone else will find the info useful.

It's going to be your MAF sensor, it could also be a bad coil, try swaping the coil and see if it misfires in another cylinder. I had both of these issues and that fixed them, should run like champ once it's replaced!

 

[anthonymtz]

Oh and always disconnect the battery to reset the ecu and trans shifts.

 

[lincolnshibuya]

I'd probably check the plug and coils first since that blinking light indicates a misfire, I'll just clean the MAF sensor for now (it's not cheap if you're buying OEM and they usually get dirty not common for them to fail) sometimes the codes are related to each other that if you fix one the other will clear out. If you drive it for too long with that misfire you'll end up killing your catalytic converters (that's also not cheap)
Use your phone to snap the codes and post it here.
Use a MAF sensor cleaner, you can buy that in walmart or any parts stores.

 

[jimborasco]

Thanks to everyone for the input! Yesterday, changed the coil and NO MORE MISS! Can't feel it, no blinking CEL, no hesitation. The coil had looked pretty good before I pulled it off, but low and behold there was a long but microscopic crack in it along the side. Have recleaned the MAF and if the CEL comes on again (solidly) it's next on the list to be replaced, which it probably needs anyway, right? This place and the people here are a godsend to everyone that needs a little help. Any question I've had, no one made me feel stupid for having asked it and that says a lot for a forum like this. Thanks again to everyone!