car wont start on 1991 Volkswagen Golf

have a 91 golf and it wont start but has spark and plenty of gas and checked the timing and that's in also, no fuses are blown ether. Car will turn over but wont even try to fire, and out of the blue it would not start. I'm am not sure what to start looking for if someone could give me a hint i would be thankful.

Asked by for the 1991 Volkswagen Golf
Are the injectors opening? Is it getting fuel into the cylinders? Make sure there are no large intake hose leaks, and make sure the oil filler cap is on properly.