I have a 2002 ford F-150 4.6 4x4 with 44,500 miles. last night it started chugging underload, and the service engine soon light came on. the code was a po308 misfire on number eight cylinder. could anything else cause a misfire (mass airflow sensor) other than the coil? They cleared the code. it continues to run like crap, and now the service engine light won't come on. what cylinder is number eight? is the COP a straight boot or a 45 boot?
thanks for the help, Joe

 

I'm having the same issues but also a P0316 code in cyl 1. Cyl 8 is on the drivers side last one back (good luck). I've swaped out my COP and plugs and still getting the miss so now im going after the crank position sensor. I'll let you know if that clears it up.

 

Both of you have to stop with the guessing or you get no-where.
First, why clear the code and not the fault? That does not help much of anything.
If you have a cylinder code, pull the coil off and the plug out and see what you have. A mass air meter only passes air to ALL the cylinders.

A 316 code is a detection of a miss in the first 1000 rpm after startup.
It's not enough to pin down a fault unless you go looking for it and have some luck or look at the PCM stored fault history that caused the history to be recorded. This you can't do with a reader.
This is not going to be the fix but first steps in knowing what you are trying to do.

 

I agree , both of you are lucky to have fault codes in memory. There are many who have these problems without a fault code/codes directing you to the general area where it exists.

Start with a good look at the specific cylinder to see if there is anything obviously wrong. If not , work from the plug out.

Good Luck.

 

will i have to remove the fuel rail to get the COP for #8 out? Is this a hard job, and can anyone give me pointers on removing the fuel rail if I have to? thanks

 

Nah, #8 isn't that bad. You might have to remove the brake booster line. It's a good idea to tape the 7 mm socket to the universal - then the universal to the extension when working on that one. Or, you may be doing allot of this - &%$#!@!$%%# in no time

 

Well after much uneeded work the problem turned out to be a bad coil on cyl #1. I would recomend not trusting the clerk at AZ when he says he can test the coil. If you get a 301-310 code just swap the bad one with a known good one and see if the code goes to the swapped cyl.

 

Wow, I also had a misfire on 8 in my 02 4.6 at 44k...your truck isn't gray with a 5 speed is it? My problem was the COP. I checked the codes, swapped that coil with another cylinder then drove it awhile and checked codes again...the miss followed the coil.
If your truck threw a code the first time it should do it again if you drive it enough. #8 is the rear cylinder on the driver's side. Not a fun one to change but no need to pull the fuel rail. I think you do need a universal to get the coil bolt out. With your low mileage the coil boots shouldn't be stuck in the holes yet which makes things much easier.
Good luck, be sure to hitch your pants up good before you kneel up on the radiator support, the neighbors appreciate it.

 

All fixed. put a new COP on #8 and it is running smooth.