HEI-ESC System

The detonation sensor translates mechanical vibration into an AC voltage. This voltage typically runs on top of an DC reference voltage provided by the external detonation module.

The detonation sensor translates every vibration into AC output voltage. The stronger the vibration, the higher the amplitude. Detonation creates the strongest output.

The detonation module ignores all signals below a certain threshold as none-detonation noise, but retards timing for all signals above the threshold (detonation).

Beware of clearance in the valve train, or a loose trailer on a hitch, as they may create sufficient vibration to be considered as detonation.

If a tip-in hesitation is occurring and a tip-in sensor is being used, be sure to check it for proper operation. It works by triggering the detonation module to provide extra advance when the engine vacuum falls below an unspecified range.

As noted earlier in the DESCRIPTION section of this article, the engine will not run without the four-connector and detonation module connected, and both modules working correctly.

For a no-start situation, the detonation module can be eliminated from the circuit by unplugging the four-wire connector at the distributor and jumping terminals "A" to "C" on the distributor side of the connection. If spark returns, the detonation module or related wiring, power, or ground is faulty.