pls help my new golf is having some serious running problems

hello there, i have a mk2 golf gti 16v year 89.
the car drives ok but as soon as u let your foot completley off the acalerator it cuts out straight away, at first it was cutting out every now and then but it is doing it every time now. Another thing i noticed is that the rev counter stops working when you switch the lighs on, the front fog light comes on the dashboard when the sidelights are on and the onboard computer has gone crazy and works every now and then when it does works it gives off insane readings which i am sure arent correct. the car has got uprated cams and has recent new fuel pumps, lifter and fuel filter pls help this car is driving me nuts p.s the electrical problems only started when the car was cutting out all the time????
regards danny lismore

I'm unsure of which engine mgmt. system you might have in the UK. Can you tell if it's CIS (identifiable by silver or black fuel distributor w/braided stainless fuel lines to the injectors) or AFC (has a arched black & aluminum air flow meter attached to the air filter box and electrically controlled fuel injectors). I don't think they made the 16v w/AFC, so most likely it's CIS. Unfortunately CIS fuel pressures are difficult to read which leaves alot of guessing if you don't have the special gauges.