1995 Pontiac Firebird high idle

Every time I start my car it goes to 3000 rpm and keeps go n up no matter if, it's n, gear or neutral. It will, go 55 mph with touch, n the gas. I have changed the idel position sensor it did not help. Every once in awhile it will start normally and idel right tell I shut it off. That's one out of every 50 starts or more. I have checked all the vacuum hoses.