Throttle Position Sensor: Testing and Inspection

Fig. 14a Disconnect throttle sensor connector.:

1. Operate engine until normal operating temperature is obtained.
2. Connect a suitable tachometer to the engine.
3. Disconnect electrical connector (BY & GB) Fig. 14.

Fig. 13 Connecting voltmeter to throttle sensor terminals (GY & LGY). W/carbureted engine:

4. Connect voltmeters to each terminal (GY & LgY), Fig. 13.
5. Start engine and decelerate engine speed from 3000 RPM and ensure current flows to both terminals simultaneously. The engine speed should be 1000---1200 RPM.

Fig. 15 Preparing test light.:

NOTE: The testing light as shown in Fig. 15, can be made and used in place of steps 4 and 5. In this case, the test light turns on when current flows.

Fig. 16 Adjusting throttle sensor.:

6. If the current does not start to flow to both terminals simultaneously, remove throttle sensor adjusting screw cap. Adjust current flow timing, turning the adjusting screw in for an earlier timing and out for a retarded timing Fig. 16.
5. After adjusting current flow, install cap onto adjusting screw.