ello kessa
your problem with the brakes is sounding to me like your front brak discs are warped? a new set of discs and pads will probably sort it!!, (unless your new to the mk4 golf which has ABS (anitlock brakes) which does when pressed extremely hard gives a on/off feel to the brakes to prevent skidding, the best way to tell is to brake gently at around 60-70 mph and if theses a slight pounding feel to brake pedal and maybe a slight 'wobble' ont he steering wheel then your discs are warped, so a bit of cash is required to sort this!! (not sure on prices off the top of my head but i think ?60 ish for discs and ?40 ish for pads from vw)
right as for you engine prob, (hard to explain if your not mechanically mided btu hear we go!!), 1st off you want your air filter checking (maybe dirty or inlet pipe clogged, (hence the up/down revs as engine trying to decide how much fuel is neede for the amount of air) if its dirty replace this 1st as its easy to do and not costly ?7 i think from vw, if the problem still persists then i think it maybe your MAF sensor on its way out (this sensense how much air is going into the engine and adjust fuel level accordingly) these are a comon fault on all of the mk4 range there about ?75 on an exchange basis form vw, i dont think theres alot more to think about with yours being the 2ltr 8v model until these have been checked/cleaned/changed, then if prob were still to persisit then we could think about other possilbe probs??
hope this helps a little??
Gaz
