1990 corvette 350 tpi ..i just did my intake manifold gaskets put everything back together and my car is hard to start and when it does the idle shoots up to 3000+ rpms

what could cause this it was running fine prior...

 

could the problem be cause by my iac...i did the coolant bypass and i didnt plug the holes that i cut where the hoses ran to also and i didnt put the gasket back in cause i figured it didnt need it could that be messing with the iac in any way?

 

If you're talking about the gasket that is between the bottom of the TB and the IAC housing then yes that may be the problem...

What holes did you cut and where?

 

the tubes that the coolant hoses connect to is where i cut..trhe problem is fixed and that was what fixed it