Fuel Pressure Regulator for rich idle?

[wontonjohnny]

will this help if i am idleing rich?

[s3v3n]

if youre talking about turning down base pressure with your afpr ... yes this will make you less rich at idle. however, it will also make you less rich all through the rpm range (which would then be lean if it was correct before).


if you think that you are somehow overrunning your stock fpr at idle and it cant keep up, then yes this could cause you to be rich at idle. is your fuel pressure at idle higher than it should be? have you upgraded other components in your fuel system like fp? if so, moving to a higher flowing fpr that wont be overrun may help you keep proper rail pressure and thus correct your rich condition at idle.

[wontonjohnny]

im running 440 injectors, and my piggyback cant lean them out enough is my theory... my idle "puuttts" every 4 seconds or so and this black carbon liquid spits from my exhaust.

when i had a WB hooked up, showed that idle was off the scale rich cause it just read a constant 10 or 12.. cant remember

my other choice i guess is get slightly smaller injectors.

[mr2mike]

I'm assuming your piggyback is an AFC.

Depending on your car type.... but some car ecu's allow you to throw a FPR on there, pull back the fuel with it. Then use the piggy back AFC to add fuel in the rpm ranges where the a/f ratio gets too lean.

Should work but I know for instance Toyota, the ecu doesn't like that and it messes the electronic timing up and can cause knock and knock sensors to pop.

[wontonjohnny]

yeah still running the AFC hack, OBD1 conversion didnt work out due to my car having a 3 wire IACV, maybe that will be my next thread title. 3 wire IACV help

[sugoi240]

AFC won't help.
I have to get a PFC to correct for it.
An AFPR can be used to balance the idle and ensure
close to factory pressure, but at higher rpms, you will still
be running rich. A PFC has a map points for 400 possible combinations, a AFC has 12, or was it 15.

[Paradox]

if your car is turbo why not just use a rising rate fuel pressure regulator and bypass the stock fuel intake completely?

[superboost]

^ thats what an AFPR is dude. He is asking whether or not he should run it.

It will not help with idle.

[RickDaTuner]

Get your self a Scaling MAF, retune...