What should Fuel pressure be?

Rob Kelly

Active Member
May 24, 2018
19
5
I'm having some issues with my 1.9tdi 2010 Leon.
It has started cutting out when the throttle is shut and the car slowing down. It won't re start until the fuel system is bled (removing return pipe from HP pump to filter) or as the RAC guy did, spraying easy start into the inlet. I've replaced all relays relating to engine control and fuel pump etc.

I'm thinking the the common rail pressure is dropping too low (HP pump tired or air in pipes) or the sensor thinks it is too low I'm getting no faults from the OBDeleven reader but will try live data later on.
So does anyone know what fuel pressure is too low or high, or even fuel temp low or high?
 

Rusty2k

Active Member
May 12, 2013
498
57
I don't think the 1.9 PD has any active fuel pressure monitoring on it. There should be a port on the tandem pump for connecting a fuel pressure gauge though.

Rail pressure should be 7.5 bar I believe, with the return line not exceeding 1 bar.

Don't forget to check the tank pump too.
 

Rob Kelly

Active Member
May 24, 2018
19
5
Ah ok, thanks for your reply. I've managed to find a bit of information on it regarding the type of injectors they are.
As i'm getting no faults up and the thing cuts out at low rpm i'm thinking its the tandem pump.
The tank pump does run and seems to give good pressure.
I'll buy a set of pressure gauges and test it starting and running to see what i get.
 

Rob Kelly

Active Member
May 24, 2018
19
5
Turns out it was the electric tank pump not getting a feed all the time. The other issues were air.
 
DPM Performance