I've been going over the FSM procedures for injection pump removal because my gasket there is leaking and lately it has gotten worse. I also plan on replacing the oil cooler lines while I'm at this job.

Studying the procedure for inj. pump removal and replacement, the FSM contains two separate procedures for replacement, one that includes using the locking pin and one that simply requires the engine to be set to 24-deg bef. TDC and the pump installed with the driver and pump-shaft marks aligned. The locking pin method requires the marks to be aligned with driver four degrees aft and engine timing set to 15-deg after TDC.

I can't really discern any noticeable advantage between the former and the latter method given the start of delivery must likely be advanced or retarded after delivery anyway.

Then again, I was wondering ...

Is it possible to avoid having to adjust start of delivery, given the delivery is already aptly timed, by using the locking pin to lock the current start of delivery in place prior to pump removal? Is it even possible to insert the locking pin before removal of pump (seems like an extremely tight fit to get the thing between the block and the pump)?

Was wondering what everyone's thoughts were on this, and why the FSM calls for a specifically different timing set when using the pin.

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1983 300CDT -- 177K