Diesel Fuel Lift pump

wild3bill · Post by **wild3bill** » Tue Feb 10, 2009 10:26 am

Is the injection pump the only fuel pump in a TDi ? A Haynes manual says so. I thought there was a lift pump in the tank to push Diesel through the filter. Book says TDi injection pump sucks Diesel from the tank through the filter just like my old Rabbit !

Quantum TD · Post by **Quantum TD** » Tue Feb 10, 2009 3:43 pm

It depends on the year TDI you have. 1994-2003 have just the rotary pump (I think), and the 2004-2006 TDI with the PD motor has a lift pump, but no rotary pump. Each injector acts as it's own pump (both pressurizing the fuel, and injecting it).

caveman · Post by **caveman** » Wed Feb 11, 2009 5:26 pm

After much disagreements and online screaming [you know-WITH CAPS ON] i realized the lift pump doesn't even work all the time. It is only there to circulate fuel when it gets too hot, it then circulates it through the cooler. This was because i was converting a PD to veg oil, and was trying to figure out if it needed an extra lift pump for the VO. In the end i just installed a lift pump with a switch so that the person could switch it on when there was a lack of power.