Regarding black smoke and hesitation when on turbocharger boost, I have checked all hoses in and out of the turbocharger, two gaskets on the blow off valve, intercooler and turbochager hoses and pipe and on the intake side of the engine. I could not find anything that looked even suspicious. Still, the engine shows good vacuum at idle and upon releasing the gas pedal, but black smoke comes out the tailpipe as soon as I hit 5 psi of boost which refuses to go any higher despite G valve that allows over 12 psi.
Regarding IAC, it opens and closes when I directly connect 12 V to middle pin and ground either outside pin. The harness female connector shows 12 V between the middle wire and either outside wire, finite ohms between the wire that opens the IAC and engine ground, but infinite ohms between the wire that should close IAC and engine ground. Is the signal to close IAC not getting to it and why. Engine wire harness is in new condition. What is the problem at ECU end?