kgarguilo wrote:Source of the post I will say, I think my idle is a little low, I will likely do a tune up (Plugs, wires, Rotar and Distributor cap) as suggested by a few and also replace the MerCruiser Idle Air Control Motor - part number 18-7697 as well. Hopefully that will raise my idle a bit.
Unless you have the floating idle function your idle speed is set by the ECU at the spec which I am not sure of, check the spec for mefi 3 , 454 mpi engines. You cannot overcome that as the ecu will always try to recover that rpm by adjusting the iac idle opening.
A tune up can't hurt, as smooth is better, but unless the counts are way off for the iac then I wouldn't change that. Just remove ,inspect and clean the air port and throttle plate, check if there is a filter on yours, some had that feature and it could become plugged affecting idle quality, but then you would see the counts way off idle spec. Cap, plugs, rotor and wires and make sure the wire routing keeps away from ( doesn't touch ) any major engine/battery grounding points/connections.