mk3 golf wont idle cuts out
 

i have a 1996 gti golf that wont idle it starts ok and runs fine when pressere applied to throttle pedal, i have done the following
1. removed throttle body and cleaned out and replaced
2. removed all air/breather pipes and replaced(one pipe was blocked solid)only pipe not replaced was one from throttle body into bulk head.

i was advised that it could be the ISV but after finding out price i want to be a little more sur and make sure there is nothing else i could check


also not sure if any connection but the lid of the brake fluid resivour has a blue peg/pin sticking out of it you can push it down but it floats back up could i have info on this to thankyou.

Mine used to idle like that, my mass air flow sensor was toast

vaccuum leak?