Changing injector pulse rate at idle?

[Peter Wales]

To get this thread back on track, I remember that the Mitsubishi turbo cars
had an injection system which was split into two sections. On boost the
injectors would fire TDC and BDC with pulse widths proportional to boost
pressure.

Below boost, the air flow rate was measure by an ultrasonic flow meter which
gave out a pulse train, of a frequency proportional to the air velocity. The
injection system injected once every 12 air meter pulses at a fixed pulse
width of 1.5  or 2 mS. The PRF adjusted the fuelling and this seems to be
what is happening in Johns car, but I have no experience of it in this car

Peter