Been having cold start and idling issues with my VP 5.7 GSI (PWTR). The engine will start immediately if I hold the throttle open in neutral and will idle fine as long as I keep the throttle handle pushed forward and the RPMs around 700-900. As soon as the throttle is pulled back the engine rpms sink and it begins to stumble and eventually stalls. Under load running after warm up appears to be fine, but holding a steady idle with the throttle in neutral is not consistent making docking a chore. I have replaced the rotor, cap, plugs, plug wires, IAC valve, ECT, MAP sensor, both hi and low fuel pumps and the fuel filter/water separator . All with OEM parts. I also cleaned the TBI. Still have same idle and starting issues. I have only owned the boat for 2 seasons and had some idle issues that appeared to be cured for a while with the installation of a new IAC valve last season, but these same issues have arisen again this season. Going through some old maintenance records provided by the previous owner, I see where he was experiencing some high idle issues a few years back. The shop included an entry that pointed out "HI Idle--Computer scan--adjust min air so IAC works better--IAC will need to be replaced soon". My question is how is the min air adjusted? Is this a computer re-flash procedure or an adjustment to the base timing? From my experience dealing with auto engines, I know that adjusting the timing even slightly will change the engine rpms. I have the codemate reader and understand how the timing needs to be adjusted while in service mode but before I tinker with that I'd like to get some ideas. Thanks