The ignition key controls the fuel pump ---- if your key is on your fuel
pump is pumping. It pumps continuously at high pressure into the fuel
pressure regulator which in turn controls the pressure going into the fuel
injectors. The ECU controls the injectors.

Cheers,
Doug

>Does the air flow meter turn the fuel pump on and off or does the ecu do
>it in combination with the distrubutor pick up.  I have a four pin air
>flow meter
>                       Thanks
>                                Greg