Computer Advance Test

1. Run engine until normal operating temperature is reached, then disconnect carburetor switch electrical connector. Check to ensure that coolant sensor is operating.
2. Disconnect and plug vacuum transducer vacuum hose.
3. Apply 16 inches Hg vacuum from outside vacuum source to vacuum transducer.
4. Increase engine speed to 2000 RPM, wait one minute, then check amount of spark advance timing. Refer to "Electronic Spark Control Specification Charts" for specification. On certain models equipped with an accumulator, the accumulator must be allowed to time out with the carburetor switch disconnected before checking spark advance.
5. If spark advance specifications cannot be obtained, replace Spark Control Computer.