Pressure on fuel pressure regulator

[Skara]

Hello guys,

Just one question regarding FPR because I couldn't find the info anywhere. Does anybody know what is the pressure on FPR should it be same as the fuel pump or different I suspect the FPR is faulty on my car and I have ordered a new one but it is adjustable with pressure gauge and now I am not sure which pressure I should set it to. The engine is C20NE.

[Robsey]

Fuel Pressure on a C20NE is
( Motronic 1.5)

1.8 to 2.2 bar. (Feed)
0.3 to 1.5 bar (Return).

With the vacuum pipe connected.

[Skara]

So FPR being on a return line I should be seeing anything from 0.3 to 1.5 on pressure gauge which is on the FPR ?

[Robsey]

That is how I read it - yes.

If the gauge is on the feed hose.
1.8 to 2.2 bar.

If the gauge is on the return hose
0.3 to 1.5 bar.

I presume setting will be during idling,
therefore close to 1.5 bar on the return hose.
(When the injector pulses are at their shortest).

And when revving, no less than 0.3 bar.

[Skara]

Thanks for the info Robsey

[vexorg]

The return pressure is a bit meaningless.
All that matters is the pressure without the vac hose is the rated value (guessing 2 or 2.5 bar for yours), and ulitmately the feed pressure is higher.
Remember at idle then it;s completely different to driving, at full load the pump will be doing a lot more work.
Injectors are another that could give similar symptoms to a dodgy regulator or pump.

[Skara]

Thanks for the input, the car is stuttering under sudden acceleration not necessery hard but sudden even if it is just a little bit of gas, most of the things are changed I just want to rule out the FPR and check the pressure on the rail

[iangsi]

I had a similar problem turned out to be a unseen split in the vacuum pipe going into the FPR, worth a look.