Cold Start Injector: Description and Operation

Cold Start Injector Circuit:

Purpose:
To provide extra fuel to enhance cold start operation.

Operation:
The cold-start injector sprays a finely-atomized mist of fuel into the intake manifold plenum. It has a normally closed plunger valve. Power is available to the cold-start injector during cranking only.

A thermal timer controls the ground circuit for the cold-start injector. The timer mounts in the thermostat housing, and is sensitive to engine coolant temperature and injector on-time.

When the contacts of the timer are closed, the cold-start injector sprays fuel during cranking. A heater coil inside the timer receives power whenever the engine is cranking, affecting the bimetal arm of the contact assembly. This will prevent the operation of the cold-start injector during repeated cold temperature starts.