[dcb]

yah, the clamp on piezo sounds like it can give you both rpm and pulse length and be easy to install, but it is a bit of signal processing to code or hardwire to make sense of it, and newer tdi use lots of little pulses which really ramp up the resolution demands on the cpu.

Older mechanical pump diesels certainly could use such a system, but if there is a computer adjusting the line pressure or making really tiny pulses it can get tricky.