You could have a leak in the IAC itself or the vacuum advance diaphragm. Maybe you don’t, just an easy thing to check. Maybe try a different MAF and fuel temp sensor too if you haven’t already.RG tells me the tune is 3361
Not really. There are four manifold vacuum connections: to IAC solenoid (doesn't leak), to oil separator/PCV (doesn't leak), to fuel pressure regulator (doesn't leak), and to charcoal canister (haven't checked). Not sure if smoke machine would show anything with the charcoal canister, but... it might.