my buddies 91 G2 idles at 3000 and we have been through the entire motor, i found no vacuum leaks, all the hoses are hooked up correctly, tps is brand new iac is brand new also, i played with the adjustment screw on the throttle body, anybody have any possible idea what it could be?
Jeff
Did you check the battery & alternator ? Is the alternator putting out enough voltage ? Do you have any Fault codes flashing on your ECU?
you mess with the timing recently? It might be that
Ken
it’s not the timing, cause it’s idling at 3000 rpm
if it was the battery or alternator, it probably wouldnt have enough power to rev it that high
I know it may sound obviuos, but something similar happened to me during my swap. Check to make sure that the throttle cable isn’t binding. The only way I found it was that I bumped the cable while it was idleing and it droped down. 
tried that yesturday, but there was play in the cable
turboteg1.8
Make sure that the TPS sensor is reading 0.5 volts close (idle) and 4.5 volts when fully open (WOT). Normally is it’s way off, you would see a check engine light. Car doesn’t need to be running but your key needs to be in the “on” position.
HTH
good luck!!
1.7NA