There were some posts about this a few days ago. I had this problem with a
1994 Mk 3 Golf GTI 16V. So did my neighbour with an 8-valve GTI of similar
age. Both cases were cured by a mobile tuner who disconnected the hose from
the air filter and cleaned the air intake. He said this is a well-known
problem. However, it doesn't seem to be known to my local VW main dealer,
nor of course is it part of the service schedule (though clearly it ought to
be).
Hope this helps.

think mine needs a clean too, my new gargage told me if the valve gets
stuck at any point from dirt etc it can stop hot air going to the injection
and cause the fuel to freeze if this happens he told me to pull over for
5 mins, scary thought thinking your fuel could freeze. or was it just the
injection freezes can't remember.