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Home >> GMC >> 1989 >> Forward Control 6.2 J, Standard >> Repair and Diagnosis >> Engine Performance >> System >> Fuel Injection System - Diesel >> Adjustments >> Injection Pump Timing
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Injection Pump Timing

  1. Original factory injection pump timing is designated in two ways. First, the injection pump is marked with a static timing mark (straight line scribed across both the pump flange and front housing). Then the injection pump timing is dynamically checked and marked with a dynamic timing mark (a circle scribed across both the pump flange and the front housing).
  2. For the engine to be properly timed, the two halve of the dynamic timing mark (circle between pump flange and front housing) must be aligned. The engine must be off while the timing is being set. A service pump is not marked with a dynamic timing mark and should be timed using the static timing mark.
  3. Check alignment of injection pump timing marks on top of engine front cover and injection pump flange. If timing marks are not aligned, loosen 3 retaining nuts, and align mark on injection pump with mark on front cover. Tighten nuts to 30 ft. lbs. (41 N.m) and adjust throttle linkage.