When do fuel pumps activate

kirkm5238

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T6 Pro
Hi do the fuel pumps prime when ignition turned on I’m sure when I got the van I could here it pumping when ignition was on but here nothing now when van first fires in the morning get a slight judder not every time if you give it a bit of gas it goes straight away ran it though vcds both pumps work tank and the one next to fuel filter but when they come on sounds like air in the system if that makes sense thanks
 
Hi do the fuel pumps prime when ignition turned on I’m sure when I got the van I could here it pumping when ignition was on but here nothing now when van first fires in the morning get a slight judder not every time if you give it a bit of gas it goes straight away ran it though vcds both pumps work tank and the one next to fuel filter but when they come on sounds like air in the system if that makes sense thanks
Or could it be a glow plug problem
 
Or could it be a glow plug problem
Fuel pump primes when doors unlock and drivers door opens, after unlocking listen to the whir, that is the HPFP priming

Similarly the starter battery livens up and causes a draw each time you open the drivers door
 
Fuel pump primes when doors unlock and drivers door opens, after unlocking listen to the whir, that is the HPFP priming

Similarly the starter battery livens up and causes a draw each time you open the drivers door
Thats only on the petrol TSI.

The Diesel only runs the lift pump when cranking.

..
 
@mmi can we get a link back to the testing that was done before?
 
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@mmi can we get a link back to the testing that was done before?
Here you go:
 
Sorry for not knowing how to start a new tread,
but I have 1 question about my T6 diesel (CXFA engine)
What if I interrupt the 12V-power of the fuelpump, as a way to prevent enginestart by an unauthorized driver?
I mean the fuel pump in the tank, not the Hi-pressure-pump.
would my mod harm the system?
Thanks for answering.
Jan.
 
Sorry for not knowing how to start a new tread,
but I have 1 question about my T6 diesel (CXFA engine)
What if I interrupt the 12V-power of the fuelpump, as a way to prevent enginestart by an unauthorized driver?
I mean the fuel pump in the tank, not the Hi-pressure-pump.
would my mod harm the system?
Thanks for answering.
Jan.
The fuel lifp pump is in the tank. And pwm controlled.

It's not advised to disable.it as a way of immobilisation as you could run the HPFP dry, which will destroy it.

The HPFP is directly driven off the engine.

Have a look at other security methods.
 
 
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