ADV5 - Check Vacuum Advance

Vacuum Chart:

Air Pressure Chart:

Vacuum Advance Check:

^ Disconnect and plug the vacuum hose.

^ Apply vacuum to the advance diaphragm and monitor the ignition timing. See chart below.

^ Remove vacuum and apply air pressure to the advance diaphragm 68.9 kPa (10 psi MAX). Monitor the ignition timing.

^ Compare the readings to the chart below.

^ Does the vacuum advance operate properly?

YES -- Check the vacuum hoses for leaks, cracks, breakage, and proper routing. Service as required. Return to Powertrain Management/System Diagnosis/Procedures/Diagnostic Charts.

NO -- Replace the advance diaphragm.