funintheteg3

iTrader: (1)

So I believe I recently experienced a failure in my fuel pressure regulator and need others opinions.

Current setup: LS/VTEC with GSR head
Stock head ex for upgraded valve springs
8.9:1 static compression ratio
Drag Manifold
57 trim T3/T4 turbo
650 cc injector
Walbro 255
18 psi

The previous owner of my Integra installed a Holley fuel pressure regulator seen here. I HAD the fuel pressure set to 52 psi at idle and now its resting at 60 psi at idle. The car went from idling at 1100 RPM to 1500 RPM and will no longer hold the tuned air fuel ratio of 11.5 to 12.0 while under boost. Now as boost increases to 18 psi the a/f will steadily increase to 13 or 14:1 which obviously isn't ideal.

So I'm left wondering what could cause such a sudden decrease in performance and how my base fuel pressure could increase without me making an adjustment. Any input would much appreciated.

Mikey3000

is the jam nut tight? what was the timeline between the fuel pressure being where u had it, and it increasing? a year, a month? it may not necessarily be the fpr, there are other factors that contribute to fuel pressure such as injector not firing, which may be why your a/f ratio went lean.

funintheteg3

iTrader: (1)

The jam nut is tight. The car went from running perfectly fine at 5:30 yesterday on my way home from work to its now horrible condition while cruising around at 11 last night. I can understand the injector idea but the car does not have a rough idle and does not stumble at any time. I also checked the fuel pressure with the engine not running and its still around 60 psi which is well over what it was before. That would eliminate an injector not firing.

Mikey3000

how can you check fuel pressure w/o the engine running?

funintheteg3

iTrader: (1)

I have a gauge mounted on the top of the fuel filter and I had one person tell me the fuel pressure as I cycled the key.

I have changed my focus from the regulator to the fuel pump. Its over 8 years old and I can imagine its seen better days.

funintheteg3

iTrader: (1)

Well figured out my problem. Kinda feel like a newb but its all good. I utilized the tiny vacuum port on the back of my GSR intake manifold to supply boost/vacuum to my fuel pressure regulator and after turning up the boost to 18 psi it conveniently blew that vacuum line off and I couldn't hear the leak over my exhaust. So not only did was the car idling at 1500 rpm but it left the fuel pressure at idle at 60 psi and caused the car to run lean under boost. Interesting set of problems. Glad I could notice the problem. Zip tied the vacuum line back on and were back in business.

RickyLee53

As was just going to suggest this, as you normall pull about 8psi vac and this would also make it lean on boost. Glad you sorted it