Vacuum Advance Check
WARNING: This page is about a different car, the 1991 Jeep Grand Wagoneer. However, it is still accessible from the selected car via links, so may be relevant.
- Start and warm engine to normal operating temperature. Connect vacuum hose to vacuum advance mechanism. Observe timing while engine speed is at idle. Slowly increase and hold engine speed to 2000 RPM.
- With vacuum applied, ignition timing should advance sooner than with centrifugal advance alone. At 2000 RPM, the vacuum advance should causes total advance to be more than with centrifugal advance alone.