4.3 high idle how do you adjust it?
 

92 s-10 blazer 4.3 high idle how do you adjust this?

CPI or TBI?

Either way, it is controlled by the ECU via the IAC valve. Base idle air setting can be changed, but first you have to verify that the IAC valve is doing its job and that you do not have other contributing factors (namely vacuum leaks).

it is the non vortec motor. it doesnt appear to have any vaccum leaks i did look for that. what is the iac valve an how do you check if its doing its job?