1991 Pontiac Firebird HELP wont start

I have a 91 firebird, its a one owner car, the car has been serviced at the dealer since new but had it stored for 2 years, trying to get it running for my daughter, the car cranks over fine, when its cool in the morning it will fire but cough and splutter, if you touch the trottle it dies, ithas new cat and exhaust, new fuel pump, drained tank and replaced fuel, new fuel filter, checked the fuel pump relay its working, exhaust isnt plugged, I took of distributor cap today and the shaft is rusty, is this normal on these 3.1 v6 motors, its getting fuel so im thinking spark any ideas thanks in advance Gary