Idle Air Control valve

[Dave K]

Can someone explain what the idle air control value does?

If this valve was ng would it effect the engine performance when running at low speeds?

Thanks

[robert theisen]

Can someone explain what the idle air control value does?

If this valve was ng would it effect the engine performance when running at low speeds?

Thanks

It controls how much air is let in to the intake to maintain idle while the engine is non loaded vs loaded and compensates to maintain a steady idle.Only found on fuel injected and injected boats. not on boats with carbs.

[chpthril]

once off idel (throttle open), the IAC is tits on a boar.

[bigdaddy_houseboater]

We carbies have them too.. they are just called "idle jets", and on the edelbrock (carter / weber) they are located on the front.

It controls how much air is let in to the intake to maintain idle while the engine is non loaded vs loaded and compensates to maintain a steady idle.Only found on fuel injected and injected boats. not on boats with carbs.

[chpthril]

We carbies have them too.. they are just called "idle jets", and on the edelbrock (carter / weber) they are located on the front.

no, no not realy.

[bigdaddy_houseboater]

Im intereted your explanation of the idle jets on a carb... and how the function of them is different from that of the EFI. I have built nothing but carb motors all my adult life, and it sounds like the function is the same.

[chpthril]

Im intereted your explanation of the idle jets on a carb... and how the function of them is different from that of the EFI. I have built nothing but carb motors all my adult life, and it sounds like the function is the same.

Ive built both carb and EFI motors, rebuild carbs and taught advanced EFI driveability. ill be glad to explain when I get some time

[Wickedcummins]

Your Choke on a carb would be more like the Idle control valve. For cold starts

[bigdaddy_houseboater]

Ah... ok then.

Your Choke on a carb would be more like the Idle control valve. For cold starts

[bigdaddy_houseboater]

Never mind.. I will look it up.

[bigdaddy_houseboater]

Ok.. Im schooled up now. Its a solenoid operated valve controlled by the engine computer that allows air to bypass the throttle and controls idle speed, unlike an idle jet that regulates the fuel flow into the intake from the carb at idle. Both are tits on a boar when you step on the pedal....
Close enough?

[dom w. forte]

On a computor controlled engine , the fuel, spark advance and idle are all controlled by the ECM, the throttle plate on a carburator had a screw to adjust the flap for more air, so when the engine needs to idle up or down based on load the computor regulates the idle control solenoid , which is a bypass port directing air past the throttle plate, it either fails open or closed but wont effect overall performance, ive seen them fail closed and people will try and adjust the throttle plate like a carb., this will cause a performance issue because they have now altered the TPS adjustment.
I hope this answers your question.

[tip22v]

My IAC muffler (Merc 350 MPI) came up missing after I had my boat winterized last year (at a Tige Dealer Service Center). The dealer claims they did not remove it, is it possible that it got injested? The motor is running perfectly this year so if it somehow got injested it has not affected the performance, at least yet.

Dealer says the loud sucking sound from the throttle body to the IAC is normal, but it never made this sound before they winterized it.

Any ideas?

Thanks,

Tom

[mjsti]

My IAC muffler (Merc 350 MPI) came up missing after I had my boat winterized last year (at a Tige Dealer Service Center). The dealer claims they did not remove it, is it possible that it got injested? The motor is running perfectly this year so if it somehow got injested it has not affected the performance, at least yet.

Dealer says the loud sucking sound from the throttle body to the IAC is normal, but it never made this sound before they winterized it.

Any ideas?

Thanks,

Tom

When I got my (new to me) tige this past spring, the IAC muffler was missing. I noticed the loud intake noise but thought it was normal until I came across a posting here with someone mentioning the IAC muffler. I checked mine and sure enough if was MIA. $1.40 later, I still can't believe how quiet it is. The part# for your 350 mag mpi should be 35-863829.

[tip22v]

I finally received my IAC muffler in the mail, the part was $1.42 and shipping was $7.99, go figure. Anyway I installed it and everything is quiet again. As previously stated, it's amazing how that little piece of porus foam can quiet the engine noise!