I had the same problem with my 1.4 golf mk4 - apparently this is a common fault with VW's - I got the fuel injection and fuel pump checked out and cleaned and it resolved it for a couple of years then the problem came back - I was advised not to run it low on fuel (as the rubbish from the tank comes up and clogs the injection)- There was also a number of other people with the same problem - varying from a dodgy relay and also faulty ignition - hope this helps
sharon
January 2009