How to Check Distributor Specifications

The following procedures should always be followed when checking any distributor specifications.

1. The distributor part number should be verified for the particular vehicle calibration number.
2. Check and reset, if necessary, the initial timing to that specified for the particular vehicle calibration. The correct procedure, initial timing, and rpm at which it must be checked are specified on the Vehicle Emission Control Information Decal located in the engine compartment.

3. Using appropriate instrumentation (i.e., timing light with adjustable advance capability or, if not available, mark the crankshaft damper in 5~ increments up to 60~ total), proceed to verify engine spark advance as follows:

a. Disconnect and plug the part throttle advance vacuum hose at the distributor diaphragm.

b. Increase engine speed in neutral to 2500 rpm and record spark advance.

c. Connect the part throttle advance vacuum hose to the distributor diaphragm and again record spark advance.

d. When necessary, consult the shop manual for the appropriate distributor assembly repair/replacement procedures.