Hey guys and gals. My truck 97 4.6 has developed a pretty bad miss once it warms up. I am thinking ignition coil. I have a question. I haven't hooked my reader to it yet. But how do you test a coil? I have a multimeter and everything else I would need. I know pulling the codes and comparing the out cylinders would narrow down the coil. If they are related to the same coil.

 

Switch coils c if the problem.follows or go out in the dark pull wires off one by one with truck running watch for.an arc that's how I did it

 

best thing to hook a reader up and see if ya get any codes, should tell ya exactly what coil(s) is bad, otherwise like said above move coils around til ya find which one is bad or do the night vision test, if ya have access to a heat/thermal gun/detector think ya can use that to after the engines been runnin to find the cooler cyclinder which should have the bad coil and misfire

 

You can check the coils with a multimeter. Get a Haynes or Chilton's manual-they have step-by-step instructions. Pretty easy to do.