This misfire to me sounds like one of three things. 1)bad ignition wire or cracked distributor cap. Start the engine at night in the dark. There will be a light show being put on by the cap and wires if they are bad. Bring your video camera.
2)The coil is intermittent. Are you using the MSD coil Jon recommended? I went with the Crane.
I simply have been screwed by MSD's lack of reliability and the kiss my a ss attitude that the company has. Your mileage may vary?
3)You may still have a bad module in the distributor. I stayed with my Motorcraft solid state distributor. Simply put, you simply can't beat the dependability. Look at the IEC installation instructions again. Any of these distributors just need a two wire hook up.
The Motorcraft you can always get the module for if it broke on the road.
4)You may need to make sure that one of the wire tabs, Faston's, you installed on your existing wire harness to connect internally to the P-E built in tabs isn't loose or partially grounding on the case. It's a tight installation inside of the case and that easily could have happened to you.
Best of luck in your hunt...oops, four things!
