Another one for the Gurus

[Gippslander]

Hello all I am having an intermittent problem with the in tank electric fuel pump, I thought it was the pump so replaced it with a completely new unit. It worked a treat for a week then stopped, I tested electrical circuit and it appears to have power when the key is switched on the relay is working. I swapped relays just to be sure but it wouldn’t run. I removed the pump again and tested it no issues, reinstalled and all good for a couple of starts then no go. I did note if it starts and I drive anywhere stop the engine and don’t remove the key it will start next time every time. If I stop the car and remove the key it may or may not start I can hear the electric pump start and I know it will run but if I can’t hear it I have to keep trying.
i believe the fuel pump is part of immobilisation system does anyone know if this could be causing the issue and more importantly how I can fix it.

Gippy

[Gippslander]

Well I got it sorted it was nothing to do with computer/immobiliser in the end but fault in second electric fuel pump, it is replaced and no more issues. I believe the brushes are either sticking hence the intermittent problem or they are worn out either way fault was in the pump.
Gippy[biggrin]

[theelms66]

Well I got it sorted it was nothing to do with computer/immobiliser in the end but fault in second electric fuel pump, it is replaced and no more issues. I believe the brushes are either sticking hence the intermittent problem or they are worn out either way fault was in the pump.
Gippy[biggrin]Is that the pump just in front of left rear wheel. ? . Mine was faulty, would start ok but had no power whatsoever.

[Gippslander]

Is that the pump just in front of left rear wheel. ? . Mine was faulty, would start ok but had no power whatsoever.
Yes it was that pump from what I now understand the in tank pump starts the process by pumping low pressure fuel to the second pump which boosts the pressure to the common rail mechanical pump. The second pump needs to supply fuel at sufficient pressure before the engine management system will allow the engine to start. This is done to prevent damage to the high pressure common rail pump from running dry, the high pressure pump has metal components that require lubricant and the diesel is the lubricant.
Gippy