Chart A-9, Cold Start Injector Valve
Cold start injector valve is used to provide additional fuel during crank mode to improve cold start-ups. This circuit is important when engine coolant temperature is low because other injectors are not pulsed "ON" long enough to provide the needed amount of fuel to start.
The circuit is activated only in the crank mode. Power is supplied directly from the starter solenoid and is protected by a fuse. System is controlled by a cold start fuel injection switch which provides a ground path for the valve during cranking when engine coolant is below 95°F (35°C).
The switch contains a bimetal material which opens at a specified coolant temperature. This bimetal is also heated by the winding in the thermal switch which allow valve to stay "ON" for 8 seconds at -5°F (-20°C) coolant. The time the switch will stay closed varies inversely with coolant temperature. In other words, as coolant temperature goes up, cold start injector valve "ON" time goes down.
- Disconnecting distributor 4-way connector will disable the other injectors. The amount of pressure drop depends on the temperature of the engine.
- This test will determine the continuity through the switch to ground.