2020 Pump Timing

[H15]

Is a timing light required to check timing advance on a Stanadyne pump using a plastic timing window?
 

[LJD]

No. The timing window has degrees marked on it. No timing light needed. Just a working eyeball. Each mark signifies 2 pump degrees and that equals 4 engine degrees. Just rev up the engine and see how many marks the timing line moves. Usually around 7 degrees on the degree-window which equals 14 degrees of timing advance movement at the crankshaft. The injection pump only runs at half engine speed so pump RPM equals 1/2 engine RPM, and pump timing degrees equal 1/2 engine degrees.