i have and i 've used a piazzo clamp on my injector lines to give my timing light a reading...my light had some issues..i may have to use it soon like today or tommarrow..as my pump will not work with my dial indicator..the plunger has too much lift.. ie the plunger is fully extended before it reachs the bottom of the plunger travel...i have alonger throw adapte rto try but the timing light idea would work the same way especailly if its a digital style ..program in say 28 degreees and boom turn the pump while its ruinning and stop it when its at the right setting.. the dodge deisel and tractor guys use it sometimes.. its very accurate if your piazzo is clamped correctly. piers in bc ha sdone this and spill port time is very very accrurate...also.....any how both snapon and mac make diesel piazzo injection line clamp timing light adapters..i can look up my adapters compnay but it was very nice but a lot less then the sanpon..snap on my wallet haha my friend blakes dad has had and used a piazzo style along with the dial indicator for over ten years ..so its not something new ...and it works finelet us know how its works for youthanksDeo\x/ hillfolk!
To answer the question you originally asked. Noone knows the timing spec for using a timing light. You are breaking ground. If you insist that your method is easier than the conventional one, I would suggest that you use another vehicle for determining the spec. You should use a similar model engine with *new* injectors and rebuilt pump and set the timing correctly. Then measure the timing on that engine to determine the spec for yours. Personally I think the dial indicator is the way to go. If using the indicator is too difficult I would go by ear. If installing the dial indicator on the pump is difficult, how the heck do you service the engine??Andrew