6.2L stalling at idle. Ideas?
 

Idling out of the marina yesterday, one engine cut out and would crank but wouldn't turn over. So I slowly cruised out to the cove on one engine.

Let it chill for about 20 minutes and she turned over. Runs like crazy once she's under throttle, no difference between it and the port engine.

When she idles, she has a slight miss. I think I am going to change the spark plugs, who knows when that was last done. Just got the boat in November with ~150 hours.

I have a spare cap and rotor at home. Ordering a fuel filter too. Anything else I should be doing before next weekend?

Just had my throttle cables replaced, could this just be a screwed up install?

If it runs fine off idle but does not want to idle it is most likely the IAC valve.

+ 1 million

Yep, IAC is bad.

Thanks guys...sounds pretty clean cut. Do you guys happen to know the part number?

www.mercruiserparts.com Type in your engine and serial number, it will take you to a break down. You can also use a car one if you do a search on here I think it was mentioned in a thread. and buy two so you have one when the other one goes.

Thanks so much. I think I found the thread:

http://www.offshoreonly.com/forums/d...iac-motor.html

Make sure the pintle looks exactly like the one you take off

Compare prices, last time I found a car one it was almost exactly what BAM gets for them.

Also I was told if you take the little foam piece out on the new one they will not go bad. I was told that filter causes the problem. I took both out when I replaced my two.

When I picked up my boat last year with a 2001 6.2L it had that issue, with a new IAC valve the problem was solved immediately and no issuses since. I am curious about the trick with the little foam piece though.

I have the foam muffler in my throttle body (496). I've replaced it once as it was looking dirty. 325 hours on the original IAC so not sure the foam is a problem as long as it doesn't plug up. I carry a spare IAC valve as I know I am on borrowed time. I'm afraid to change the original out as it has lasted 3 times longer than most. The new one probably will shoot craps after 100 hours!

One thing I am curious about: this engine has also been running richer than the other. More soot on the transom. I imagine the tune up will help. Does the IAC help this or is there another thing going on?

if the IAC is not working properly, it could be causing a rich condition at idle and therefore the soot.

IAC first if it does not clear up and still runs rich try to have the motor scanned to see how the MAP sensor specs out. MAP sensor might be the problem of the rich condition if IAC does not clear it up.