91 camaro idling high

I have a 91 camaro rs with a 305 (5.0L) throttle body injection that is idling at 1700 rpm. I have replaced the tps and the iac, cannot find any vacum leaks, the check engine (dummy) light is not on. The butterflies are closing all the way, could an intake gasket leaking cause it to idle this high ? Any suggestions would be appreciated. Thanks

a leaking intake gasket could do just that, check it by spraying a little choke cleaner around the edges of the intake, if the motor pitch changes its leaking.

I'll try that and see what happens thanks for the help.