GM Chevy Mid-Size Cars 1964-1988 Repair Guide

Anti-Dieseling Solenoid


See Figure 1

Beginning in 1968 some models may be equipped with an idle speed (idle stop) solenoid on the carburetor. All 1972-75 models are equipped with these idle solenoids. Due to the leaner carburetor settings required for emission control, the engine may have a tendency to diesel or run-on after the ignition is turned off. The carburetor solenoid, energized when the ignition is on, maintains the normal idle speed. When the ignition is turned off, the solenoid is de-energized and permits the throttle valves to fully close, thus preventing run-on. For adjustment of carburetors with idle solenoids see the section on carburetor adjustments in Engine Electrical of this guide.

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Fig. Fig. 1: Anti-dieseling solenoid