injector flow rates

[02sierra4x4]

do they need to be referenced to vaccum? if you leave them at one flow rate for all vaccum levels wont it just affect the VE table percentages? is there a benefit to referencing them to vaccum? thought crossed my mind thought i would ask!

[joecar]

For manifold-referenced fuel pressure regulator:
the IFR table is one value flat across;
the reason being that the MAP referenced FPR maintains a constant pressure difference across each injector.

For non-referenced fuel pressure regulator:
the IFR is sloped (curved actually);
the reason being that the FPR maintains constant absolute pressure, so pressure difference across each injector varies with MAP.

The injector flow rate varies as the squareroot of pressure difference, so PCM has to lookup the flowrate.

More Info: if you're comfy with maths, read this:showthread.php?t=4821 (http://forum.efilive.com/showthread.php?t=4821)

:)