Trying to fix this problem for a fellow RX7 guy. When the ignition switch is turned to the start position it fires and runs, when it goes back to the run position it quits. If you hold the key switch just off start it will stay running. Upon further inspection a 81 distributor was installed. He tried another key switch but that didn't solve the problem. What do you think of bypassing the ballast resistors (if in fact a resistor coil was used)?
Its a 79

 

keep trying until you find a good ignition switch.

could also be a hack wiring job of the ignition, check to see where the coil power is coming from: switched or crank only?

 

Check your fuses. The ignition gets power from a different circuit when it is in the start position. if there are no bad fuses then there is a bad connection somewhere.

When this exact same thing happened to me it only a fuse. Of course I didnt find it until I had replaced the ignition switch!!!!!

 

bypass the ballast resisters
what is happening is that as you crank, a relay bypasses the ballast blocks and gives the coil 12v

this relay is provided for all the old school cars that came with points

when you let go , the relay drops out and you are left with around 8V feeding the coils and ignitiers,,, probs not enough to run them

 

Installed new ignition switch, bypassed resistors. one coil had oil coming out it so I replaced both coils. Checked timing and it seems backwardards. Leading wire lit up on the trailing mark, and visa versa. Starts and runs fine. checked position of distributor seems to be ok, any thoughts?