Quick question: when the ecu decides to send a richer mix (i.e. AFM door is open), does it tell the injectors to spray more, or does it tell the pump to pump faster in order to force more gas through. In other words, does the pump have varying speeds based on need, or is the flow managed by a variable spray from the injector?

Thanks!

 

The ECU 'tells' the injectors to stay open longer when needed

The pump is constant speed. A fuel pressure regulator maintains correct pressure in the fuel rail by bleeding-off fuel, which is returned to the tanks

Cheers
DD

 

Ditto:

Doug beat me to the response.
His probably better than mine would have been.

Carl