fuel pressure

[ray666]

okay this is a little weird. i had to turn my pressure down because of too much fuel(i keep it ar 27 psi), but yesterday i started it up and the pressure was up higher around 38 psi i had it around 27. now so this morning i had to turn it back down, but now i have to retune. eveything was fine at 27 psi yesterday now today its leaning. do i have a pressure leak somewhere? where do i start looking?

[homeslicej2]

Well, 27 psi is too little pressure to begin with. The SR FAQ's and the FSM both state that the fuel pressure should be approx. 36 psi at idle with vacuum hose connected to fuel pressure regulator and 43-43.5 with vacuum source disconnected. You were running to little pressure to begin with. Is your fuel press. gauge acting funky maybe? What gauge and FPR are you using?

[ray666]

well the reason i had it turned down is because my injectors are 785cc. i'm using a nismo fpr and i can't remember the brand of the gauge. i know the gauge is oil filled if that matters

[OM3GA]

The injectors typically utilize stock fuel pressure settings as long as you are tuned properly. The Nismo FPR tends to be a little jumpy from what i have heard.

[homeslicej2]

well the reason i had it turned down is because my injectors are 785cc. i'm using a nismo fpr and i can't remember the brand of the gauge. i know the gauge is oil filled if that matters

Yes, fluid filled mech. gauges help make the reading more accurate and less bouncy/vibration resistant than non-fluid filled ones. I'm not sure why your tune is leaning out even though you've reset the pressure to the same as before. See below...

The injectors typically utilize stock fuel pressure settings as long as you are tuned properly. The Nismo FPR tends to be a little jumpy from what i have heard.

I think you might be right. I've only had my new NISMO FPR installed for a couple hundred miles, but I've had to adjust twice already (always down, not up). I thought it was just bc it's new and might have needed to be "broken in". So far, since the last adjustment that is, it's been holding the same pressure fine. I use the Tovic fluid filled gauge that 240sxmotoring sells. Hopefully, it's not jumpy and I won't have to readjust again. We'll see though. OP, this could be part of your issue, but I don't know for certain. I suggest you just re-tune to be safe.

[ray666]

yes i will retune. although since my orignal post i've tinkered with it a lot and i've managed to get the fuel preesure under control. now its just a matter of stopping the rich issue at idle. it will be fine, fine as in 12-13 a/f. then it will dump gas. i've gapped plugs down to .026 which helped out a lot.