Might be an interesting challenge, as the injectors are fired electronically. Whilst the pressure is provided by the camshaft it's the ECU that tells the valves to open and close. So you'd need something to convert the accelerator pedal position into a signal that could be used to control the timing and duration of the injectors opening. Hmm. I wonder what one could use? I know - a TD5 ECU might do the job!