EFIDynoTuning Forum

So I've heard a couple people online say this and was wondering how true this is. If you decrease your fuel pressure the ecu will increase injector pulse width to keep commanded lambse . Likewise if you increase pressure it will shorten pulse width. Alway in context of unturned guys cranking up fuel pressure with adjustable regulator l.

If you decrease the fuel pressure you will have a smaller injector. A small injector needs to stay on longer to deliver the same amount of fuel as a larger injector.

If you increase the fuel pressure you will have a larger injector. A larger injectors needs to stay on for less time to deliver the same amount of fuel as a smaller injector.

Only the returnless fuel systems that have a rail pressure sensor will automatically correct for this. A return style fuel system will need the new injector data inputted in to the tune for any changes in fuel pressure. The ecu will not automatically adjust the pulse width on its own it needs to know the new injector size to do so otherwise dropped the pressure will cause lean out and raising the pressure will cause enrichment.

I'm pretty sure it will adjust, it will just be using the LTFT to do it, at least when in closed loop.