After reading the many posts concerning 4.6 "missing", I think my 4.6 has a bad coil but don't know how to id which one. I've got 80,000 miles and have changed all plugs which looked good. Computer at a local mechanic showed no errors. Ford dealer wants $$$ to hook to their computer with no guarantee to id which coil. Any suggestions on determining the bad coil? Thanks.

 

You can take your truck to Autozone and they will read the codes for you for FREE, it should be a P030? depending on wich cil is causing the misfire.

Good luck

 

What year is your truck? If it's a 97, then it would be cheaper just to get new coils than have the codes read. Even if it doesn't cure it, and upgrade to MSD coils certainly couldn't hurt.

 

If you have a decoder and it is a 1997 (don't know about other years) but the code number will tell you which cylinder is misfiring.
Had the problem on my 1997 F-150 and the plug was bad. The OBDII system will also shut off the injector on the cylinder that misfires. Cool system. The coils if original are numbered for the side they are on. Good luck.

 

It was a coil pack. I bought 2 more new Borg Warner cop's from O'Reilly's for $49/each and replaced all the coils on the driver's side. Couldn't tell by looking as to which coil was bad but the missing is gone and the engine is back to it's normal purring self. Hard problem to solve considering that the missing was so erratic and the fuel rail on the driver's side had to be removed to replace the coils. Don't want a hot engine/exhuast when removing that rail. All is well now, but that was an annoying problem in that no dash lights ever came on during the whole ordeal. Thanks for the suggestions.