Operation CHARM: Car repair manuals for everyone.

Throttle Full Close Switch: Testing and Inspection


On most systems, grounding the carburetor switch eliminates all spark advance.
1. With ignition key in Off position, disconnect 10-way electrical connector from computer.
2. With throttle fully closed, connect an ohmmeter and check continuity between pin 7 and ground. If there is no continuity, check wire and carburetor switch. Recheck basic ignition timing.
3. With throttle opened, check continuity between pin 7 and ground. There should be no continuity.