How do I adjust my fuel pressure to the right amount of boost?

[RedTopDrifter01]

I have a rb20det with tuned ecu, front mount, intake 3.5 inch exhaust, walbro 255 fuel pump, T28 turbo the car runs so rich and it has trouble starring and idling I run 10 pounds of boost and I don't understand how to adjust my fuel pressure to make it rum correctly with that much boost without running to lean or to rich. I'm going to be installing a turbosmart adjustable furl presure regulator in a week. Can anyone help me to understand how to fix the problem?

[fliprayzin240sx]

You sure its the fuel pressure and not the "tuned" ecu having too rich of a map?

I hope you got a gauge to figure out what your pressure is at. Also, how the fuck are you gonna figure out if its too lean without a wideband o2 sensor.

[RedTopDrifter01]

I have a fuel pressure gauge with the regulator. The car ran fine until the pump was put in and everything was already in the car already so I don't really have a clue. My A/F gauge dosnt even barley read it when I stomp on it its so rich. I also was told that my o2 sensor could be fucked and that would cause it to run more rich is this true or just a bunch of bullshit.

[240sx123$]

Tuning off of fuel pressure is GHETTO. Your fuel pressure should be constant, and at OEM settings. The ECU tune is how you adjust your a/f ratio.

You need to get it on a dyno with a wideband, find out where your a/f ratios are, and adjust accordingly.

I thought people stopped tuning with fuel pressure back in '79.

[Darius]

The fuel pressure regulator increases the fuel pressure with boost at a ratio of 1:1. So if you are running a baseline fuel pressure of 43 psi and 10 psi of boost, you should be seeing 53 psi of fuel pressure under boost. It is good that you are replacing your fuel pressure regulator because it sounds like either it is not functioning properly or something else went wrong (i.e. bad tune or fuel injector sticking open).

[Sileighty_85]

Not sure if RB20's have the diagnostics LED, but if it does check the ECU for codes.

almost sounds like the CTS (ccolant temp sensor)

[RedTopDrifter01]

Thanks for the information, first I'll try to read the codes and see if anything comes up.