Important information, below, provided by Bob Senter (International Lugger/Northern Lights Service) which I was not aware of. Bob has been advising Don McIntyre on his injector pump problem.

To prevent injector pump failure is very important that fuel supply vacuum levels, when operating, do not exceed 6HG. Often a momentary RPM increase signals fuel starvation. If an immediate filter change is not practical using the priming pump to create a positive fuel pressure may save your injector pump.

Injection pump failure usually causes on those is when the lift pump fails and the operator continues to drive too long causing excessive stress on the injection pump. The injectors are not usually affected...

here is a small article that Bob wrote http://www.seaskills.com/files...rationWhitePaper.pdf

Another important tip from Bob Senter is that to NEVER use anything smaller than a 10 Micron filter in your IN LINE engine racors. Anything smaller will create too much vacuum/constriction. It is OK to use something smaller in your POLISHING racors. I think I remember reading that Don was using filters smaller than 10 micron. This probably contributed to the damaged injector pump.