Checking Enrichment Circuits

CHECKING ENRICHMENT CIRCUITS

Test Conditions - Engine temperature must be below 68°F (20°) or the temperature switch terminals must be bridged. The oxygen sensor wire must be connected and the dwell meter should be connected to the test plug. Start the engine and follow the instructions below.





Check temperature switch:
Below 68°F dwell meter should read 72°, above 77°F dwell meter reading must pulsate.
If the dwell meter readings are not correct perform electrical checks. See Troubleshooting Electrical System.
If no electrical problems are found replace the control unit.





Check temperature switches:
Below 68°F dwell meter should read 72° (temperature switch 1) between 77°F and 86°F dwell meter should read 59° (temperature switch 2) above 104°F dwell meter reading should pulsate.

Check full throttle switch:
Bridge the fuel pump relay and activate the fuel pump. Press the accelerator pedal to the floor. The dwell meter should read 59° (engine warm).

Check the starting enrichment circuit:
Ground the coil wire and crank the engine. The dwell meter reading should he 72° (engine warm).
If the dwell meter readings are not correct perform electrical checks. See Troubleshooting Electrical System.
If no electrical problems are found replace the control unit.





Check temperature switch:
Below 86°F dwell meter should read 72° above 77°F dwell meter reading should pulsate.

Check full throttle switch:
Bridge the fuel pump relay and activate the fuel pump. Press the accelerator pedal to the floor. The dwell meter should read 59° (engine warm).

Check the starting enrichment circuit:
Ground the coil wire and crank the engine. The dwell meter reading should be 72° (engine warm).
If the dwell meter readings are not correct, perform electrical checks. See Troubleshooting Electrical System.
If no electrical problems are found, replace the control unit.