Td5 Fuel Pump Hi Lo Pressure

[Ollie]

I have searched and can't find an answer.
I changed the fuel tank for a long range one, went through the bleed sequence, power on press the throttle pedal a few times until the engine symbol flashes pump cycles four or five times pedal down key to start, the engine tries to start then just turns over on the starter. Some smoke from the exhaust.
Checked the pump hose connections colour coded and correct.
Removed the pump ran it with test leads and battery low pressure output produced fuel. Refitted pump cracked the return from the injectors to the regulator some flow but not 180 ltrs.
Has anyone had a pump with the low pressure operating but not the hi pressure?
The pump was changed and has lasted 30k up to now it runs quieter but it is now in a steel tank.
Regards Ollie

[sierrafery]

You shoulld check the pressure with a gauge instead of the FT sensor in the FPR, if you get 4+ bar there the HP is OK, though it's not uncommon at all for the TD5 pumps to loose HP and work only on LP

make sure that the battery voltage doesnt drop under 10V while cranking cos then it will just happily crank but not start cos the ECU needs more than 10V to work with the injectors

[strangy]

Its possible but unlikely that a tank change will coincide with a pump failure.
Despite the colour coding - Double check the fuel line configuration matches this.
https://encrypted-tbn3.gstatic.com/images?q=tbn:ANd9GcT6HdLu594ftdCRjBnMioLnK5BQYMYN4 Cf5tOjoqW958_jcAzvr

[crash]

Has anyone had a pump with the low pressure operating but not the hi pressure?
The pump was changed and has lasted 30k up to now it runs quieter but it is now in a steel tank.
Regards Ollie

Yes has happened to me - and occurred after having my injector seals done.
With no lines connected the pump would work pumping out fuel but with all the lines connected not enough pressure to start. New fuel pump and all was okay.

[Ollie]

Hi Thank you for your replies
I will get a test point for the FT sender port Sierrafery but don't have one at the moment do you know what size and thread it is?.
Replaced the fuel pump with one known to work no change.
Replaced the original injector loom (been meaning to do this) after the Nanocom finally came up with three different injector faults on three different occasions after clearing faults, also disconnected the DP Chip.
Started and ran first turn of the key!
Reconnected the DP Chip and the fault returned, no start.
I have disconnected the DP Chip with all its wiring, Has anyone ever heard of this type of problem before?
I did not think of this it is hidden away next to the ECU
Regards
Ollie