Hi

Trying to help another garage to sort out this rr which could not top 30 mph. Scanned for codes and (p)1260 low primary fuel pressure was present. Rigged up Coder fuel guage which read a max of 20psi but showed a flow of 3 ltrs/min.

Because they felt that the tank pump was slightly noisey the garage took it away and fitted a new in tank pump with new filter. Road test showed slight improvement but fault code flagged up again and fuel pressure and flow were very similar to previous readings. My thoughts are the flow rate is fine but the pressure is very low(should be 60+psi?). If the outlet of the codec is nipped to reduce flow the pressure rises to 85 psi or so- proving the pump to be ok?. I am unsure what the piping and various components do after they get into the engine bay it seems quite a complicated arrangement of cooler, filter, 3 way valves etc but i think the pressure should be regulated by something before it gets to the hp pump. Am i thinking along the correct lines or well off track.

Can anyone supply a schematic diagram of the fuel supply components please