EFIDynoTuning Forum

No, returnless will not work on the fox ecu as it does not have a pwm output available to control fuel pump duty cycle same as the explorer and 2011+ fords.

However 'mechanical returnless' is fords definition for having a short return line. Mechanical returnless uses the same fuel pump code as the return system since its only difference is a short return line. The fuel pump code for the 2011 fords and the 97-01 explorer ford copied from the 83-95 eec-iv.

okay, that is a very useful piece of information... I wasn't making a distinction between returnless and mechanical returnless.

if the Holley sender claims to send 58psi with the built-in regulator in the tank, i guess that makes it mechanical returnless. does that obviate the need for a PPRV?

i see that you recommend always running at 65psi base pressure for the kind of injectors i'll be using... is trying to run 58 psi on an A9L a matter of changing a scalar value, or would I be starting my tuning journey by walking through the gates of hell?

on a related note, are you still doing remote tunes?

pprv is a regulator so all good

you simply plug in your injector data for which ever injectors your running for the pressure your running just as normal

yep still do

alright then, i think i have enough information to proceed... if all goes well, i should be getting in touch about dialing in a base tune in the coming months.

thank you so very much for the info and advice.

yep np