Hi all,i'm having problems starting car after it has been stood for a while.I'm a very long distance truck driver and havent been back for 3 weeks.Yesterday after been stood for 3 weeks it took about 10sec of turning key to fire up.sometimes this may or may not happen after just week.In feb whilst in Austria it stood for a week at -20.c and fired 1st time,i'm thinking battery(still original) or its diesel draining back to tank.

I have not had a diesel for 20 years, do you have a glow plug light, you used to have to wait till it had gone out before you started it and if your glow plugs were knackered ,you dturned on( ignition again ) and gave it another go to start. It will be your battery or the glow plugs. Diesels do take a lot of power to crank over. While a typical V8 gas engine may use about 300 to 400 amps electrical power in the starter to crank the engine at temperatures below minus 20C, a diesel starter will use almost double that. Most of the power is used to compress the air. Gasoline engines have compression ratios around 9.5:1 (the amount of times the air is squeezed or compressed in the cylinder during the compression stroke). Diesel engines use compression ratios of 16:1 up to about 20:1. The higher compression ratios used in diesel engines gives them better efficiency, but makes them harder to crank.

Taken from another post