Assuming it is diesel, it sounds like one or more of you glow plugs are dead.
Easy to test. Pull them out, get a piece of electrical wire and put one end on the terminal on top of the plug and the other on the + pole of your battery. Then earth out the body of the glow plug on the - pole of the battery. Keep your fingers clear of the end that goes into the cylinder as it will get hot within 10 secs if the plug is not faulty. It will glow a orange colour if it is good. If it is bad it will remain cold. Throw it away and buy a replacement.
PM me if you need a hand. I can help you out this weekend if you need it.