Fuel Pump Prime

[Deleted member 70421]

Hello,

Can someone with a 2.0 TDi 170 confirm whether they hear the pump prime when opening the drivers door? Or should it only do it when ignition is on?

Cheers

 

[Phil-1]

I have never heard my pump when opening the door. I struggle to hear it in the car when I switch it on.

 

[j4yvw]

hi mine is the same it only primes when you switch it on. The issue i have is if i don't use the car for a few days it will not start straight away, it takes a coulple of cranks to fire up.
So what i do now is to prime it a few times and it fires on the first crank.

 

[Deleted member 70421]

hi mine is the same it only primes when you switch it on. The issue i have is if i don't use the car for a few days it will not start straight away, it takes a coulple of cranks to fire up.
So what i do now is to prime it a few times and it fires on the first crank.

Thats the very same issue I have. Trying to get to the bottom of it as it's getting worse to start from the first cold start of the day. As in takes around 8 goes before it starts.

Noticed its more when the car has half a tank or less of derv left.

 

[Johnny Bravo]

I have the same problem: http://www.audi-sport.net/vb/a3-s3-...hen-fuel-less-than-half-tank.html#post2172753

I've recently got a used in-tank pump from a friend, for testing and the starting problem has gone.
I'm going to buy a new pump.

The problem is that there is a one-way valve on the circuit that should prevent the fuel to drain back in the tank. This valve is failing and can't keep the system pressurised.

A lot of details here: 2005 BEW PD lift pump operation and internals - TDIClub Forums