i own a 87 GTA and have not drove it for the past 2months, it was running well. it starts fine but sometimes turns off, and when driving sometimes it does not rev higher than ~2000 and it drops the revs and the car starts to want to turn off ans some times it does. for example turn car on, put it on D and even if i push all the gas pedall in it just wont rev higer than ~2000, and the revs start falling. however saometimes it runs good no problems it shifts and revs well. HOwver when in P and N i can rev the car up to ~7-8000 but it will reve untill 2000rpm then it wont want to rev higer it will sort of get stuck in 2000rpms and sudennly reve higer.

any ideas what can be wrong???

 

I had a similiar problem. Turned out that I had water in the gas.
I put in about 1/2 a bottle of 91% rubbing alcohol. Dried it right up.