Fuel Pressure 48psi

[ilovemys13]

I'm wondering if 48psi at idle is too much. There's no pick up so I'm wondering if it's choking up because of the pressure.

Sorry, this is probably a noob question

[ilovemys13]

I searched around and nothing really clearly says anything about that....

[PandaS14]

stock fuel pressure under vacuum is 43psi, so 48 is ok. will be just a tad richer than the ECU thinks it is/was designed for.

[InsanityInc]

er, you definitely have a problem. Stock under vacuum is 34psi. Stock without vacuum is 43psi

Have you replaced your fuel pump with any kind of higher-flowing one? That will cause your fuel pressure to go up with the stock regulator.

[ilovemys13]

er, you definitely have a problem. Stock under vacuum is 34psi. Stock without vacuum is 43psi

Have you replaced your fuel pump with any kind of higher-flowing one? That will cause your fuel pressure to go up with the stock regulator.

not that I know of, I bought it off a guy who didn't know what he was doing. He might have tried some stuff.

So is the high pressure related to my problem with acceling/revving off idle?

[PandaS14]

er, you definitely have a problem. Stock under vacuum is 34psi. Stock without vacuum is 43psi

Have you replaced your fuel pump with any kind of higher-flowing one? That will cause your fuel pressure to go up with the stock regulator.

My bad, I had it backwards. 43 is with engine off, not idle. what was I thinking? haha

[InsanityInc]

not that I know of, I bought it off a guy who didn't know what he was doing. He might have tried some stuff.

So is the high pressure related to my problem with acceling/revving off idle?

It's certainly a possiblity. High fuel pressure will make your car run rich whenever the ECU ignores the signal from the O2 sensor, which only happens two places: At WOT (specific to our cars, because of the wonky WOT fuel map), and below 2500 rpms or so (this is because the O2 sensor isn't heated, so it only works when the exhaust is quite hot). So basically a high fuel pressure will make you run rich at low RPMs, and put more strain on your injectors (mine started leaking from it). You could have a kink in the line, or you (or the previous owner) could have done something to the fuel system

Either way, the best way to fix it is to get the NISMO universal AFPR (the "240sx" one doesn't fit at all, don't buy it), and then get creative with some fuel lines. I can take a picture of how I attached mine if you need me to.

[ilovemys13]

okay thanks, yeah after mesing around we think we've got it figured out so thanks guy