Delphi Flexible Multipoint Flexible Injection System (Spider)



YZF-R125 Notes:

Fuel tank has no return, static pressure per manual at idle is expected to be 36.3psi, service manual has a write up of EFI system and implies constant pressure.  Interesting.



Ok, I didn't understand why EFI 'return' fuel systems have the regulator connected to the inlet manifold.  But now perhaps I do..

Main takeaway (linear 1-1 regulator): goal is to maintain a constant pressure differential across the fuel injectors. Pressure across injectors is fuel pressure +/- inlet manifold pressure.