Results 1 to 2 of 2

Thread: Rossion Fuel Pressure Regulator

  1. #1
    Join Date
    Jul 2016
    Rep Power

    Default Rossion Fuel Pressure Regulator

    Looking to understand the fuel pressure in a stock Rossion. It has the standard Bosch 3 bar FPR. Would anyone know if this is a rising rate FPR and what is the rate of rise (is it 1:1)? What should the base idle fuel pressure be, with the vacuum hose disconnected? What should the fuel pressure be at wide open?

  2. #2
    Join Date
    Apr 2007
    Rep Power


    It’s fairly straightforward- the Bosch FPR is a 1:1 regulator, so the fuel pressure is maintained at 3 bar above whatever pressure/vacuum is present at the reference port. Since the reference port is hooked up to the intake manifold, you should be able to measure the manifold pressure, add 3 bar, and come up with the expected fuel pressure. For example, at idle, the manifold pressure is around -0.7 bar, so your fuel pressure should be (3 bar + (-0.7 bar)) = 2.3 bar or 33 psi. WOT fuel pressure depends on how much boost your car is making - measure the amount of boost in the intake manifold, add 3 bar, and you’ll get the expected fuel pressure.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts