poorly car, ISV advice anyone pleeeeease ? !

[laura80]

hi i was wondering if anyone can give me some advice on this isv please, after being laid up for about 4 months, my 86 gt coupe has decided not to run properly, she was fine when i left her (apart from i smashed up one of the original rear alloys, hit a rock doing 60 OUCH) so she could just be peed off with me!!
symptoms are :-
starts fine from cold, ticks over perfectly at just over 1000, almost immediately it will start to slow and then die. wont start again for about 5 mins.
also if i give her any throttle straight away she dies even sooner.

i have tried many things, including;
new leads plugs vac hoses dizzy cap rotor arm, checked for air leaks. etc,
new air filter , i cleaned the isv, but the spring inside seems a bit slack,
should the valve be well sprung inside?
also i think i scratched the inside of it with a screw driver. stoopid i know.
could it be the injectors even though it seems to start and run perfectly for a couple minutes? does my car have an ECU could that be the prob?
anyways thanks in anticipation sorry for the essay!