IAC Valve

aero3113

I was considering buying a spare Quicksilver IAC valve for $160.30 from Amazon. A while back @YYZRC asked me if I was going to replace both of mine. After thinking, since I don’t know when mine were last replaced, I’m going to replace them both and keep the old ones as spares. It’s crazy that Quicksilver wants $160 for one. I did some research and found this EMP IAC from Michigan Motorz . EMP seems like a very reputable company and attends many boat shows to display their products. I was able to get two cheaper than one Quicksilver. Hopefully this is a quality part and will be just as good or better than quicksilver. FYI , for some reason Michigan Motors has these listed on eBay about $10 cheaper with free shipping. Since these fail often, it would be nice to find a cheaper option that is meant for marine use.

https://www.michiganmotorz.com/mercruiser-idle-control-valve-sensor-p-11088.html

EMP website:

https://www.engineeredmarineproducts.com/phone-index

YYZRC

What's the symptom if an IAC fails? 

aero3113

You won’t be able to idle.

YYZRC

Well that would suck!

Can you post a pic of where the IAC filter goes? I need to do that when I get on the boat after COVID lockdown. 

aero3113

Yes, hard starting and stalling at idle.

PickleRick

There was another thread in here with a diagram of where the iac filter sits.  I think it was @aero3113 who posted the diagram.  

aero3113

It’s at the base of the IAC on your engines.

aero3113

On earlier engines it’s under the flame arrester in the throttle body.

Liberty44140

Yea I had an iac go years ago on a 5.0 in my 310 and it would not idle, would start and immediately rev to about 2000 rpm. Super easy change though but there was a learning process I had to do involving starting and stopping the engine, instructions came with the part, if I recall the part was just over $100 but that was 8 years ago. Does Sierra have an offset? I’d certainly run a Sierra iac in a mercruiser. 

aero3113

Yes, Sierra does have an IAC. I’ve seen them selling between $90-$130.

aero3113

With EMP, they state they try to improve OEM parts.

PickleRick

Ive heard of guys using the motocraft or other oem automotive iac on their boats.  They are usually not painted in automotive applications.  I realize some like marine only components but I'm not sure what could make an iac automobile vs marine.

If i had them on my boat knowing they only usually last 200 to 400 hrs id have a spare automotive iac in the boat.  A 40 to 50 dollar spare vs 100 plus.

aero3113

@PickleRick , I think most of the marine IAC’s aren’t painted now. There was some research done and they said that the paint contributed to them failing. I guess they were overheating?

Liberty44140

If Michigan motorz sells it, it not crap, don’t think I’d have a problem buying the EMP. 

PickleRick

Heat soak is a huge contributor to killing electrical parts.

aero3113

Yea, @Liberty44140 I don’t know how I found out about them, I’ve bought many parts from them.

PickleRick

Michigan motors has a good reputation for reman and new inboard motors, it's not a surprise you've heard of them if you know a lot of boaters or browse forums.  

Aqua_Aura

I have seen Michigan motorz al online when looking for parts. Always wondered if they were good. They have very reasonable pricing and I like that they have plenty of remanufactured parts. 

halifax212

@aero3113  I tried the automotive one, and while it worked , the idle seemed too high. Finally went to the dealer and bought the mercruiser/quicksilver. Problem solved.

aero3113

Yea, @halifax212 . I’ve heard that about the automotive ones.

GMSLITHO

I also tried the automotive one with the same results as halifax212 and ended up replacing with the mercruiser 

aero3113

I received the IAC valves from Michigan Motorz today. They seem to be of good quality and nice that they came with the gasket.

tazdevil

if you want to use an automotive iac on a merc  you should use the right one for a merc mpi i use a windstar 2002 and works fine , i have tried many others (owning a scrap yard helps) and found that a windstar is a direct interchange with a merc mpi 

aero3113

@tazdevil I have read that people use the IAC from a windstar, good to know it works.

aero3113

https://www.rockauto.com/en/catalog/ford,2002,windstar,3.8l+v6,1385782,fuel+&+air,idle+air+control+(iac)+valve,6072

Ian

I recall when one of mine went a couple of years ago the service guy told me it was the same as the Ford Windstar and Mercury something.

YYZRC

Mercury Villager!

DanD2

On my old Monterey, I replaced both of my IAC's with Windstar one's from NAPA. It went at least 4 years before needing replacement. Much cheaper and also very easy to replace

aero3113

I got around to installing the new IAC’s. I think automotive ones were installed. I remember reading somewhere that the brass piece and spring are marine.

New one is on the left

New

Old

aero3113

FYI- The IAC has a screen underneath it. On this screen is a rubber gasket that’s attached to it and permanent, the screen can’t be removed it’s riveted on. I almost tried to scrape this off, glad I didn’t. On the starboard side the old gasket stuck to this so I just reused the old gasket instead of risking damaging the rubber. Almost makes me wonder if the paper gasket is even needed?

Spyderweb

Here's the IAC taken out of my 2007 Bayliner 285 during its 10th season.  I know it's original because I was the 1st owner.  Looks like your "old" one from the 330, lacks the bronze piece and spring.  Wonder what the extra piece does for the valve?