Volks jetta deisel 1997 won't start

You need to change the glow plugs in a diesel just like changing spark plugs in a gas. they burn out and don't heat so well, change the glow plugs and it will fire up in -30 with no block heater. you should run diesel fuel conditioner with anti jel. this keeps the diesel from jelling and not getting into the engine.

The plug is attached to a block heater that warms the antifreeze when the car is sitting. I own a 2004 Jetta Diesel that has done fine all the way down to -10F without plugging it in, just make sure to always cycle the glow plugs before you crank the engine when you first start it, that's the most important step when starting a diesel. Your car probably gets around 50 MPG and diesel fuel doesn't burn as hot as gasoline, so starting and keeping the car at it's full operating temperature on a cold winter day can be almost impossible.

DEPENDING HOW COLD OUT IT IS DIESELS DONT LIKE TO START IN COLD WHEATHER UNLESS THE GLOW PLUGS ARE WARM THIS IS THE REASON FOR PLUGGING DIESELS IN MOST WONT START IF ITS COLD OUT IF ITS NOT THAT COLD OUT IT SHOULD START IF YOU HAVE ENOUGH BATTERY POWER MAYBE THERES NOT ENOUGH FUEL GETTING UP TO THE THROTTLE BODY HOPE THIS HELPS