Stang94GT

I'm not sure if this is the proper forum for this but I've got an FD so I figured I'd start here. How does the ECU know how much fuel to inject? Does the FD use a mass air flow sensor? If so, is it a draw-through or push through type? Where is it located? It seems to me as though excess air exiting via the blow off valve would make the car run extremely rich if it were a close system using a MAF sensor. So I'm guessing but .... does it calculate air injection based on rpm, MAP sensor pressure (taken behind the throttle body?), and air temp? Is this how it's possible to simply vent air to atmosphere via the BOVs?



Is there a good primer somewhere on the net that explains all this type of basic rotary/FD engine operation?



Thanks!

papasmurf

its a map sensor behind the tb as you said. i believe it is rpm based because if fd's had a mass air, then youd be able to run dry shots and not HAVE to change your ecu.



i mean i could be wrong but it would've been cheaper on all parts running mass air, especially when upgrading, bolt up and go, not bolt, tune and go as it is with fd's

j9fd3s

the fd uses the map sensor, tps, and rpm as its main load inputs. the corrects for air temp, coolant temp, fuel temp, ac on or of, etc.



the reason you can have an open bov is because everything ahead of the throttle body isn't seen by the ecu, the ecu only sees whats after the throttle body.



most rotaries use an airflow meter, the fd is more like an aftermarket ecu



mike

Stang94GT

That's what I thought. Cool, thanks for the info!

toddp31

Have a Map sensor is better than having a mass air flow, most high hp cars get a standalone that allows them to get rid of the airflow. Mass air flow is always blocking the intake air.