Hi, I'm having the same probs with my 95 GTI. It lost all power - then it started running on 2 cylinders - now it wont start at all. I am going to look at the ignition - HT/spark plugs/caps etc. I would look at that. also, the rocker box covers are prone to leaking oil into the fuel. You need to clean out the throttle body with carb/ignition cleaner to get it to stop jumping. Also putting injector cleaner into the fuel would help - as would cleaning/replacing the spark plugs. You need to get the gasket replaced if it is leaking.
Gordon the Golf
November 2009