Mixture Control Solenoid - Slow Cut: Testing and Inspection

Fig. 12 Testing Deceleration Control System.:

1. Run engine until normal operating temperature is reached and continue to run at idle.
2. Disconnect neutral switch or inhibitor switch electrical connector(s), then remove air cleaner case assembly.
3. Connect a voltmeter to light green wire terminal of the carburetor connector, Fig. 12.
4. Increase idle speed to 3000 RPM, then lift idle switch arm and note voltage.
5. Voltmeter should indicate approximately 12 volts above 2500 RPM and less than 1.5 volt below 2500 RPM. If voltage is not within specifications, check slow fuel cut solenoid valve. Also check emission control unit 2D terminal voltage.
6. Connect a voltmeter to brown/black wire terminal of the carburetor connector.
7. Increase idle speed to 3000 RPM, then lift idle switch arm and note voltage.
8. Voltmeter should indicate approximately 12 volts above 2500 RPM and below 1400 RPM and less than 1.5 volt between these speeds.
9. If voltage readings are not as specified, check coasting richer solenoid valve. Also, check voltage of emission control unit terminal 2H.
10. Connect a voltmeter to white/green wire terminal of the coasting advance solenoid valve.
11. Increase idle speed to 3000 RPM, then lift idle switch arm and note voltage.
12. Voltmeter should indicate approximately 12 volts above 2500 RPM and below 1700 RPM and less than 1.5 volt between these speeds.
13. If voltage readings are not as specified, check vacuum solenoid valve. Also, check voltage of emission control unit terminal 1S.