Here some questions I have regarding the Bosch MW fuel pump used in the 5 cylinder Mercedes turbodiesel:

• Can I upgrade the plungers from 5.5mm to, say, 7mm without sacrificing idle?
• Is there a way to adjust the low end in the pump without touching the high end and vice versa? In other words, if I adjust the pump to deliver more fuel at boost, would it be annoyed at idle?
• I was told the pump is designed to retard fuel delivery when it gets close to its upper limit. Can that be adjusted?
• Are the fire sequence off the 5 cylinder mercedes turbodiesel and the Audi 5000 turbodiesel the same?

Thanks for any help!