Expert: Sean Halliday - 12/11/2008

Question
On two occasions i parked my Audi A4 TDI estate on a hill facing down, and it would not start. when i turned the key I can hear the ignition system turning the engine over but the engine does not spark into life. On both occasions i free wheeled the car to the bottom of the hill and it then started. On the occasions this has happened there has been about a 1/4 to 1/8th of a tank of fuel. I find it difficult to believe that it is as simple as needing more fuel - i would have thought there'd be a suction system but if i'd be grateful for any comments you have. normally (if not on  a hill) it starts perfectly. thanks

Answer
Yes i have seen this before with low fuel the feed line is on the lower of the tank but because of the incline,the fuel goes to the front of the tank and the car seems like its out of fuel.Most cars are recommended to be at least 1/4 tank especially with a in tank pump as the fuel also acts as a coolant for these pumps.Running very low on fuel is not good for the fuel pump if you do it consistently.They can overheat and fail prematurely.Did you try the same scenario with a full tank?Did the car start?