My engine started missing about 3 weeks ago and has gotten progressively worse. Idle is now ok, but it starts missing during acceleration and is extremely bad in the higher gears.. So bad that I’m forced to shift to low gear. It’s a 1993 f150 with 302 (5.0L). I replaced the MAP Sensor about 2 months ago and that fixed a problem with the idle. But soon after, the problem with missing began… I’ve tried replacing the plugs, coil, and checked the ERG Valve. The check engine light is not on, so I assume no codes… I noticed tonight that the new coil is glowing between the sides of the coil pack and the metal housing… Should it glow?? The wires also glow when the engine is reved up. They were replaced last year (8mm resistor type). I tried replacing the new coil and sam thing (It glowed even worse)...

Any advise is appriciated...

 

http://fullsizebronco.com/forum/showthread.php?t=44736No. Is it glowing like red-hot, or like a neon sign?Get a Haynes manual & a cheap digital multimeter and follow the ignition diagnostic procedure. Also, make sure yours is exactly like this:

 

UPDATE
I remembered this morning that a grounding strap between the frame and cab (near the muffler) had rusted off a couple months ago. I put a temporary clamp on it today at lunch and it seams to have solved the problem. Thanks for the input...

 

Then you have some SERIOUS other ground problems that you need to address.