fuel pressure

[clive f]

using a pressure guage fitted into the fuel rail, I set the fuel pressure to read 2.6 bar when switching on the ignition, however, have noticed that with the engine running it reads just over 2 bar, so should the pressure be 2.6 bar when running, or when engine off??


Dnb, where are you?

[Johno]

When the engines running . . .

[GreenV8S]

The pressure is relative to the manifold, so engine off you have normal atmospheric pressure in the manifold and +2.5 bar on the fuel rail; at idle you have about -0.5 bar in the manifold and about 2 bar in the rail.

ETA: to set the fuel pressure you have to have the pump running but the engine stopped.

Edited by GreenV8S on Monday 1st October 17:54

[clive f]

thanks Peter