Not passing SMOG

Hello all my name is:Lex
For my: 1994 3000GT VR-4

So the car passes everything while on high RPM, but on idle it is Rich.
Before throwing parts in random I just wanted to consult you guys on what I should focus on>

  1. Mass Air Flow sensor: Is there a difference between Turbo and DOHC NA version?
  2. Idle Air Control Valve: Might be stuck in a position that limits air on idle?

Any ideas that I haven’t thought of are also welcome.

There are a number of different maf sensors used. Do you have any smoke or error codes?

Hello, Joe.
OBD1 so no check engine light and no codes.
There is no smoke on idle either.

This is a hard one since there are no error codes, what scan tool are you using?

Running rich at idle? fuel injector cleaning and re-calibration

Fuel injection cleaning is step 3 if ICV (step 1) and MAF (step 2) do not yield desired results.
Thank you for your suggestion.

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