Basic Advance Timing Test
- Connect an adjustable timing light to engine so that total timing advance at crankshaft can be checked. Connect a jumper wire between carburetor switch and a good ground.
- Be sure vacuum line is connected to vacuum transducer on computer. Observe timing mark immediately after engine starts to run, and adjust timing light so basic timing signal is seen at timing plate.
- The meter on timing light should then show amount of advance, as indicated on vehicle emission control label.