Dean McNeill

hi i have a a6 3.2 fsi with a stalling issue , it only does this when at normal running temp. it stalls in park or when driving . ive scanned for codes none found. its like it runs out of fuel. ive replaced fuel pump in the tank , and on the engine. ive replaced the throttle positioning butterfly, ive replaced fuel pump relay and fuel pump controll unit . when its plugged in and running u can see the fuel pressure just fall , and the engine stalls, ive also replace the valve on the bottom of the mechanical pump and ive checked resistance of wires to ecu .. can u shed any more light on this please

91quattro

How about fuel filter? Maybe it's clogged? Underside, in front of the right rear tire. It's a long shot but it seems like you've done everything else.

Dean McNeill

Hi and thanks i forgot to metion this was changed at the same time as the in tank fuel pump ... thanks for the reply

hrc4u

Can you post a full vcds scan? If you have access to vcds?
/H

Dean McNeill

Hi sorry i dont have access now to scans ,,,,, The only fault tha came up was intermittent fuel pump issue ,, both have been changed and faults cleared. , after car stalled scanned again. no fault codes found , that was in feb. still have no codes found

Sam Zubel

Without VCDS scans i can only suggest to try replacing this. Try replacing the high pressure fuel rail sensor underneath the manifold on the drivers side fuel rail with a oem unit. As well as the low pressure fuel sensor next to the fuel feed line. And last, the brass check valve/ bleed/ return valve located on the passenger side fuel rail closer to the front.

Like to hear back

-Cheers

Dean McNeill

After all the issues it turned out to be the High-pressure fuel valve on the inlet pipe to the high-pressure pump ... it can be seen on the left-hand side of the car where the rubber fuel line meets a stainless steel bar, the sensor is just there .. it was disconnected and tested and didn't stall. I have replaced this,,, and believe this is also the same as the one u mention on the fuel pump

Thanks for all of your help and input

Sam Zubel

Good to hear back and issue fixed That brass sensor mentioned is low side pressure sensor for the system, also a common fail point.

-Cheers

Dean McNeill

Thanks, Sam . The funny thing was I had one sat in my cupboard ever since the car had this fault doh