Slow idle and surging 350 MAG

YYZRC

On cold start, my port engine idles very slowly and surges between 400-600 RPM. Once it warms up it idles fine. Thoughts?

aero3113

Swap IAC’s and see if the issue follows to starboard.

Dream_Inn

I agree with aero, easy thing to check first.

rasbury

Plugs and wires done last when? Old fuel in the tanks?

YYZRC

I like that plan. Will try and report back. 

YYZRC

Fuel is new. Plugs, wires, cap and rotor are big question marks. Was hoping to tackle them over the winter as I dumped my fun money into the transom assemblies and bow thruster this year. 

rasbury

It's not big money..at least comparing to that! These motors are pretty simple...

Aqua_Aura

I just watched this video of a boater I subscribed to and he was explaining this exact issue and how he fixed it. He does have Volvo 8.1 though. Did you ever fix the issue? 

There may have been another post on here I am thinking of but this is the first one that sounded familiar when I searched. 

YYZRC

Yep. New IAC fixed it. I tried the Windstar one and it did not work. Went OEM.