the other day my blazer started idling really high can be going 30mph and let go of gas stays a constant 30, and shifts really hard and late in every gear, have to give it alot of gas for it to shift. I have checked the idle air control valve and its moving back and forth when i turn the key on, also took egr valve off, its clean no carbon. no check engine light either, i'm lost anyone got an idea?

 

is there a sensor that would effect the transmission and idle speed?

 

Not really related, but a vacuum leak could possibly skew the MAP readings which may cause a firmer shift.

You need to check over all of the intake gasket surfaces & vacuum lines for signs of a vacuum leak and correct any leaks that you find. Clean the throttle body and make sure that the throttle isn't getting stuck open.