Injector pulse processing

[Wayne.MacDonald at zurich.com.au]

I am building a 68HC11A8 MPU to allow me to modify the injector pulse from
the ECU before it reaches the injector, Can anyone help be with the
circuitry I need to convert the pulse from the ECU into a suitable signal
for a 68HC11 input, I also need to be able to drive the injector from an
output on the 68HC11.

any ideas would be appreciated.
          Wayne Macdonald