Reply to "Engine misfiring"

Dougo had exactly the same problem after replacing his breaker point distributor with an MSD ready to run distributor. The engine would run, but not well. Operating the headlights or power windows would kill the motor.

He had wired the new distributor into the car using the same power wire for the coil/distributor as the oem coil had used. The MSD ignition draws significantly more amperage than the oem breaker points. The voltage drop created by the higher current as it flowed through the resistance wire and the ignition switch, left insufficient voltage to operate the new ignition.

I verified this by taking a 10 foot length of 12 gage wire with alligator clips on both ends, ataching one end to the battery positive terminal, and the other end to the proper coil terminal. The car then ran fine, power windows & headlights no longer affected the motor's operation.

The fix was to supply the ignition with battery power sourced from the starter relay, via a relay mounted in the engine bay. The relay was operated by the wire from the oem ignition that Doug had originally used to power his MSD ignition (the oringinal coil power wire).

Your friend on the DTBB, George