2001 Audi A3 1.9 tdi. I'm new to diesels so apologies if this is a silly question. I'm having trouble starting the car at the minute. I can see air bubbles in the fuel line from the filter to injection pump. I was just curious whether or not my car has a lift pump as I can't hear it prime. I looked under the rear seat and there is what appears to be a pump with a float on it for the fuel gauge, but there is only one plug connector with a positive and negative wire on it, that appears to be for sending signal to the fuel gauge. Is this a lift pump?...i'm confused.