Fuel pressure related?

[420_240]

I installed my fuel pressure gauge the other day... and to my surprise, my rb was running at 72psi of fuel...

Car was running perfect... very smooth and strong pull... idle was around 750 (estimation since i don't have a correct tach)

So i turn down the pressure to 42-43psi, vaccuum off.

Car idled like sh*t for a while... died... then i started it up again and let it run for about 15 minutes and the idle returned to normal

Took the car out for a test drive after the newly adjusted fuel pressure and it feels noticeably less powerful...

The motor feels as though it's struggling then boosts... and the boost isn't as strong of a pull as it was when set to 72psi.

By struggling i mean it kind of sputters and then it begins to boost...Any thoughts on what is happening... should i turn the fuel pressure back up to where it was set?

Help as always is greatly appreciated.

[Shahee1]

I'm having a similar problem with my RB20DET ... I was sputtering at high rpm range ... now after changin spark plugs I am sputtering at the beginning of my rev and will then go into boost ... LOL ... OH!!!! Also I sputter at about 5k on tach ... its really bothering me .... What FPR are you using???

[420_240]

Using a Nismo fuel pressure reg. and an Autometer Mech. Gauge

[USMCgetsome]

what spark plugs and you sure about that psi? I'm having the same issue. I'm running the setup with vaccum line off 43psi then vaccum line on it sets to 36psi. This is what i was told to set at by many members of nico.

[420_240]

Not sure on the plugs... XAT replaced them when they finished the car... When I got my car back from their shop, I didn't adjust anything... My fuel pressure had to have been adjusted/tuned in their shop to that PSI. Yeah I know the 43psi w/o vaccum deal... Thats what i tried adjusting the pressure to and the car ran like dogchit... Jon powell suggested that i call the shop to see if they had tuned it to that high fuel pressure... I'm calling them tomorrow morning so hopefully i'll find out by then

[USMCgetsome]

keep us posted.

[Bluefire]

stock ecu? Try and check if its throwing any codes.

-BLuefire

[USMCgetsome]

when i had my stock fpr installed and when i put in my fuel pressure gauge i read it at 70psi stock. Afterward, i installed my nismo fpr then set it to 43 then it naturally went to 36psi. I'm gonna try that tomorrow and put it back and see what happens.