Not a Big Block but this this is driving me nuts. 1991 Grand Marquis 5.0. Won't half way run, skipping, popping and black smoking. New dizzy, plugs and TPS. Wired a DuraSpark coil into the system and it runs fine, went and bought a brand new coil for this application and have the same problems as before. Check engine light on immediately upon start up with NO codes being relayed to my scanner. I'm at wits end with this one! Any thoughts and/or suggestions will greatly be appreciated. If this is in the wrong place please move it.