How do you determine proper function of vacuum advance on 22r motor?

Answer 1

To determine the proper function of the vacuum advance on a 22R motor, you can use a timing light to check the ignition timing at idle and then rev the engine to observe if the timing advances as expected. Disconnect the vacuum advance line and check for a change in timing; it should revert to a base timing setting. Additionally, you can apply vacuum to the advance unit using a hand-held vacuum pump to see if the diaphragm moves and the timing advances accordingly. If the timing does not change or the diaphragm is unresponsive, the vacuum advance may be faulty.