System Check
- Disconnect the hose from the throttle closer. Raise and support the front of the vehicle. Put the transmission in second gear and check for vacuum with the vehicle speed above 10 MPH and engine speed above 800 RPM. There should be vacuum. If there is vacuum, go to step 9).
- If there is no vacuum, check for voltage at the TC solenoid valve with the speed above 10 MPH and engine speed above 800 RPM. If voltage is not present, go to step 4). If voltage is present, disconnect the vacuum hose from the TC solenoid valve and check for vacuum.
- If there is vacuum, replace the TC solenoid and retest. If there is no vacuum, check the vacuum line to the TC solenoid valve for leaks or blockage, and the carburetor port for blockage. Clean and repair as necessary.
- If there was no voltage in step 2), check for voltage between the Orange terminal of the throttle closer control unit connector and the body ground with ignition switch in "ON" position. If there is voltage, check the clutch switch. Adjust or replace as necessary and retest.
- If there is no voltage, check for voltage at Yellow/Green terminal of throttle closer control unit connector and body ground with vehicle speed above 10 MPH. If there is voltage, check Blue wire between control unit and distributor.
- If okay, replace the control unit and retest. If there is no voltage, check the input voltage of the vacuum switch with the vehicle speed above 10 MPH. If there is no voltage, check the fuse, wiring and speed sensor. Repair or replace as necessary and retest.
- If there is voltage, disconnect the hose from the vacuum switch and check that vacuum is above 5.9 in. Hg with vehicle speed above 10 MPH. If vacuum is below 5.9 in. Hg, check the vacuum line to switch for leaks or blockage and the carburetor port for blockage.
- Clean and repair as necessary and retest. If vacuum is above 5.9 in. Hg, check the wiring between the vacuum switch and control unit. If okay, replace the vacuum switch and retest.
- If there was vacuum in step 1), connect hand vacuum pump to the throttle closer and apply approximately 15.7 in. Hg of vacuum with engine idling. Engine should stop. If engine stops, test is complete. If engine does not stop, check that throttle closer linkage moves smoothly and throttle cable is properly adjusted. If okay, replace the throttle closer and retest.