GM Service Manual Online
For 1990-2009 cars only

Inspection Procedure

  1. Inspect the distributor base for damage, corrosion, or plastic particles. If any of these conditions exist, replace the distributor. Refer to Distributor
  2. The distributor is driven by a camshaft pin that mates to one slot in the distributor driveshaft. Align the distributor driveshaft slot with the distributor base timing mark.
  3. Rotate the engine crankshaft until the number one piston is at the top dead center with the intake and the exhaust valves closed. The camshaft pin will be at the 9 o'clock position.