Bob Lunn
09/29/97 09:55 AM


> I don't think that cars with digital "miles per gallon"
> displays have flow meters in their fuel rails.
>
> I mean, think about it... If YOU were designing a fuel-
> consumption display for a fuel-injected car, would you
> get the information by installing two expensive flow-
> meters, measuring flow to the injectors and subtracting
> the flow back FROM the injectors, or would you go for
> the software-only method of simply accumulating the widths
> of the injector pulses and multiplying that by the known
> flow rate of each injector?

     Umm, well what we actually did was to use the
     sender that's installed in the fuel tank!  :)

     The most straightforward explanation for this is
     that the injector data is 'owned' by the engine
     control computer, while the trip computer is 'owned'
     by the (instrument) cluster computer.

     Even though the ECC puts its data onto the comms
     bus (and so the cluster computer can listen to it)
     it coupled the two systems together in a way that
     was unnecessary.

___Bob