[Northporter]

My 2001 Coronet 2900 is equipped with small block mercruiser V8's.  Apparently they are equipped with something called an air idle controller that kicks the throttle up when first starting.  As the engine warms up the idle settles down to about 700 RPM's from about 1200 RPM's.  My question is are their others who experience issues with the air idle controller?  My engines invariably stall unless I modulate the idle as it's settling down.  Plus I would like the engines to idle closer to 800 RPM's to eliminate spark plug knock but I'm told the idle is not adjustable?

[Uhehner]

I have removed and cleaned sticking idle air controllers. They said you can't but WD-40 did a great job.

I don't know how changing the idle to 800 RPM would eliminate knock. That's a function of timing and is not adjustable on these engines. If you could adjust the timing, increasing (BTDC) it would increase the idle speed but worsen a knocking problem.

Some engines still have an idle stop adjustment and some throttle controls have an adjustment at the helm end. You could try looking there.

Capt. George

[Northporter]

Thanks Capt George.  

What is odd is that on a cold start the controller immediately kicks the RPM's up above idle.  Then the controller allows the idle to drop and the engine stalls.  I have to increase the throttle before the controller allows the idle to drop in order to prevent stalling.  Then after the engine has sufficiently warmed up it will sit at idle without stalling.  I assume the purpose of the controller is to modulate the idle for you and prevent stalling?