ok.. well its odd..

as soon as posts came about dealing with the restrictor mod for the sfmu, i started showing signs of needing to do it..

i finally did it.. my idle fuel pressure went from 10 to 19.. i can finally boost again and at wot i dont flutter cause of being too rich.

now.. should i lower the fuel pressure back down to 10 or leave it at 19?

thanx
James

what size are your injectors? If you're idling fine (no black smoke out of the exhaust, no fuel smell, engine is not loud or shaking eradically), then leave it.

440cc injectors

James

hmmm.. maybe people are thrown off by by the word resistor instead of restrictor in the subject title..

:shrug

sorry I thought I replied to this...musta been a dream or it didn't go through or something. If it idles ok I say leave it alone...did you/can you datalog it? Or if it idles a little rough lower the idle pressure down to like 15 or something. Idunno...idle pressure seems pretty arbatray(sp) to me...beside a little stumble my car idles fine when I pull the sfmu vacuum hose off and the pressure goes from 25-30 to 40-45....never looks at the trims for that though the ECU is probably pulling quite a bit of fuel/duty cycle at that point. Hope that helps.

For 440's, I say turn it down to where the engine just starts stumbling, and turn it back up 3psi. Then retune your fuel curve with the bleeder.

The less you have to electronically compensate for the big injectors, the better.

Originally posted by micyek
sorry I thought I replied to this...musta been a dream or it didn't go through or something. If it idles ok I say leave it alone...did you/can you datalog it? Or if it idles a little rough lower the idle pressure down to like 15 or something. Idunno...idle pressure seems pretty arbatray(sp) to me...beside a little stumble my car idles fine when I pull the sfmu vacuum hose off and the pressure goes from 25-30 to 40-45....never looks at the trims for that though the ECU is probably pulling quite a bit of fuel/duty cycle at that point. Hope that helps.

Kent, I can bring my pocketlogger with me this weekend at the meet, if you want to datalog your car :) I idle at 20 psi on the 310's, with great fuel trims. I got a too rich CEL(trims maxed out) at anything over 27-29 psi at idle. I idle at 17.5 hg's also..YOu'd be very surprised how fuel pressure affects fuel trims..even just several psi.

Matt,

That'll be cool...I do have my pressures turned up a little to be safe right now...I have a pocketlogger myself but I can't find my damn palm...LOL...If I find it I'll bring it and we can still play with my pressures...thanx alot man:thumbsup