Starting help

[Raul_C4]

Considering a new ready to run distributor to replace fat HEI distributor MSD says it's compatible. Comes with its own 3 prong pig tail for the already installed ICM . So my question is If I leave the 4 prong pig tail connector unplugged that plugged into the huge HEi which looks like is attached to the ECM not too sure. If that is left unplugged will it not allow the vehicle to run ?

 

[ecss]

Considering a new ready to run distributor to replace fat HEI distributor MSD says it's compatible. Comes with its own 3 prong pig tail for the already installed ICM . So my question is If I leave the 4 prong pig tail connector unplugged that plugged into the huge HEi which looks like is attached to the ECM not too sure. If that is left unplugged will it not allow the vehicle to run ?

When the engine is rotating, the factory HEI distributor sends references pulses to the ECM. That signal is the only way the ECM knows the engine is rotating. No reference pulses means the ECM will not pulse the injectors or turn the fuel pump on after the initial 2 second prime. Two of the wires are used by the ECM to take control of the engine timing so it can advance and retard the timing once the engine reaches a certain rpm. Did you tell MSD you wanted a distributor with computer/electronic timing control and not vacuum timing control?