So i have a 1992 legacy 2.2l motor swapped into my 1986 Gl. Cant get it to idle down it wants to be at like 2000 rpm and its not the ect sensor. And i have also notices the gas mileage is not what it should be. I tried rolling the IAC Control counter clock wise to slow the idle as a last resort....it didnt like that. Because once it got warm it would drop under a 1000 rpm. And ideas would really help

Very Basically Thinking: I believe it has a Vacuum Leak somewhere...

but it also might have a MAF sensor malfunction.

vaccum leak first but yes it sounds like iac valve could be malfunctioning mass aif flow last if it starts right away its not the mass airflow trust me I know still fighting mine