8.1 IAC Valve Issues

[Bwardz50]

Hi there, I recently started having an issue with my STBD engine giving me an IAC fault 152 Alert on my SmartCraft with 2 beeps every minute or so. When the engine is cold, it now won't stay running at idle unless I give it some throttle but the RPMs still fluctuate. Through my research I decided to replace the IAC Valve but I still have the same problem and alert. I've come across many write-ups that say replacing this valve fixes this issue but for some reason, for me, it didn't. Anyone else have this issue or heard of this? Thanks in advance for any advice! -Brian

 

[mblockb]

Hi there, I recently started having an issue with my STBD engine giving me an IAC fault 152 Alert on my SmartCraft with 2 beeps every minute or so. When the engine is cold, it now won't stay running at idle unless I give it some throttle but the RPMs still fluctuate. Through my research I decided to replace the IAC Valve but I still have the same problem and alert. I've come across many write-ups that say replacing this valve fixes this issue but for some reason, for me, it didn't. Anyone else have this issue or heard of this? Thanks in advance for any advice! -Brian

Did you replace the little muffler in the throttle body as well? I replaced both but only had one IAC failure issue. Pic of melted IAC below. You may be able to wash yours if they look as bad as mine did. Also, i had read only the OEM IAC will fix the issue. Bought both the OEM and aftermarket. The aftermarket part fixed the issue so the OEM is in the parts drawer since I couldn't return it.

https://www.wholesalemarine.com/muf...GpvRT3SUhq1L16Dh8PS8XtjGQEB6ubZBoC6c4QAvD_BwE

 

[paulswagelock]

There is the possibility that the failed IAC fried the circuit on your engines ECU. So the output would not work and thus the IAC still would not control. You can check the signal to the IAC on the good motor and see if that is the same on the bad. I believe Whipple was one of the companies repairing that circuit, it was common enough for them to develop a fix.

Could have received a bad IAC new. Take one off good motor and try it on bad motor to rule that out as well.

 

[mnm99]

Exact same thing happened to me. I heard it was common so I bought 2 spare IAC valves and kept them on my boat. 2 days later my IAC and muffler looked just like that. IAC failed. Replaced and have been fine so far.