2003 SPI Misfire
 

My daughter's Focus has been having intermittent misfiring at around 45mph when accelerating. Then a couple days ago the MIL started flashing and registered a 0302 and 0316 code. It seems to get worse when accelerating.

I replaced the crankshaft position sensor but the miss is still there. I am going to replace the plugs and wires, but I'm not sure where to go from there if that doesn't fix the problem.

Any thoughts, hints, suggestions would be greatly appreciated!!

haven't looked up those codes yet, just thought I'd mention first that the plugs & wires certainly won't hurt 7 you should take a CLOSE look at the coil and it's wiring while you're at it.

On single coil Focus's, removing the coil & checking the base for cracking solves many issues with similar symptoms if cracks are found, the wiring issue is less common for a particular speed range.

luck!

Well, it seems I've got the miss fixed. The #2 plug wire had infinite resistance and the plug was wet with gas so that was my miss.

It still has a rough idle and seems to stumble on takeoff. Any thoughts on that?

Thanks,

Gary

This is the coil end of the bad plug wire. Should I be concerned that the coil has been damaged?

http://img.tapatalk.com/d/12/09/17/ymuhehyq.jpg

Think I finally got it resolved. Pulled the coil today and the #2 tower was burnt pretty bad and there were several cracks in the coil. Replaced the coil and it is idling great and the shudder is gone!!