1978 911 SC CDI problem
 

Have a 1978 911 SC. Have replaced the fuel injectors and distributor. It ran 2 times. Now it will not start. Have only the smallest faintest spark to the spark plugs. Have checked the following:
---- 12 volts to the CDI module.
---- .82 VAC from out of the impulse generator.
---- Coil reads 1/2 ohm primary to primary +-
---- Coil reads 723 ohm from secondary to primary
---- spike of voltage to the coil wires then nothing

Could the coil have shorted out and taken the CDI module? Help is needed?

Trigger signal sounds OK, so your pickup coil and green coax cable are probably fine.

Coil resistance readings are OK, so your coil isn't permanently shorted ... though it may be breaking down under load.

CDI-unit isn't fried or you wouldn't be getting any spark at all!

Have you tested the spark plug and coil-to-distributor wires for end-to-end continuity with a digital multimeter?

Have you tested the coil output directly to a spark plug ... bypassing the distributor rotor and cap?

Please test the output at the CDI-unit 'A' terminal with an oscilloscope or AC Voltmeter ... both connected and disconnected from the coil while attempting to start the engine??? The pulses should be 350 - 460 Volts in amplitude, but of very short duration. The AC Voltage reading with a multimeter will be substantially lower than 200 Volts.

The following diagram may be of some assistance:

http://www.pelicanparts.com/ultimate...hematic-1s.jpg