I have a MEP003a with a failed injector pump, I purchased a new factory reman. pump with out the timing button. When I tried to calculate the button size I come up with a size bigger than the biggest button on the charts. What can be done other than exchanging the pump for a different one? Old pump lpc 1.0899, old button is a #14 or .128, new pump lpc 1.081 which comes out to a .1369 which is larger than a #16 button the biggest on the charts.
That is a unique problem. Assuming the pump has been rebuilt properly, a button should fit. Have you removed ALL shims for the mounting? Have you tried with the largest available button? Would be curious to see how poor the timing is after you have installed the thickest button possible.