my gti overfuelling and cutting out

[yellowgti]

my mk3 colour concept is running like herbie after been dragged out of the lake!, its cutting out almost everytime i come to a junction, ive had a diagnostic done on it and it came up with rear abs sensors that ive now got and air flow meter which ive got, the guy said the air flow meter was definatly the cutting out problem, anyway i called him back out and now it says its the "throttle valve potentiometer" where is it and is this gonna solve my problem? also ive been told that the injectors are set at 4.1 and suppose to be set at 1.9 how do i change this as its only doing 18mpg and stinks of petrol
?
cheers lads

[Bazzer]

I *think* the throttle valve pot is the bit the wires go into, where the throttle cable goes.