could someone please explain what the ignition coil does..how do you know when it goes bad..

I have a strange high pitch grind when I try to start the car..turn the key off and the key out of the ignition put the key back in and it will start...but sometimes I have to roll the car back then it will start..no not the fly wheel had that replaced.

benzat
1982 380 SEC

Sounds like a bad starter drive. The gear on the starter is part of a one way clutch. It the direction the starter turns the gear and shaft are one. When the motor is going faster than the starter the gear and shaft freewheel allowing the gear to be easily retracted from the flywheel. I am interpreting your noise to be a drive that is free wheeling in the forward direction.

Simply speaking the ignition coil is a transformer. It converts 12v to 35,000v or less, whatever the circuit demands at the moment. BTW no matter how high performance the specs on the coil the firing voltage is only what is necessary to close the circuit over the largest form of resistance (usually the plug gap under load). An ignition in good shape never sees more than 15-20,000v.

the starter has been replaced also..where would the starter drive be?

benzat
1982 380 SEC

The drive is part of the starter. Hopefully you can still have a bad drive. I say hopefully as an other alternative would be that a section of the flywheel ring gear is missing (chewed up).