Component Tests and General Diagnostics

1. Start engine and allow to reach normal operating temperature, then place ignition switch in the OFF position.

Fig. 81 Connecting throttle valve switch test wire.:

2. Disconnect throttle valve switch electrical connector, insert suitable wire into upper terminal, Fig. 81, then reconnect electrical connector with part of wire directly exposed.
3. Start engine and allow to run at 2,500-3,000 RPM.
4. Apply battery voltage to exposed portion of wire. Engine speed should lower to approximately 1,250 RPM. Engine hunting may occur at 1,250 RPM, this does not indicate abnormal condition.

Fig. 82 Fuel cut & engine speed graph.:

Fig. 85 Fuel cut & engine speed chart.:

5. If engine speed does not lower as specified in step 4, check system as shown in Fig. 82, then compare with specifications in chart, Fig. 85
6. If step 5 is not satisfactory, check setting of throttle valve switch and wiring. If these parts are found to be satisfactory, replace control unit.