Engines start and idles fine. When put into gear they die. Any ideas?

Possible IAC Issue?

thanks for the response. That is the way I'm leaning. I have a scan tool. I'll have to hook up and see what going on.

Are those mefi 3's ?...........kinda strange its happening to both at the same time

I am WAAAY over my head here but I wondered what AIC was and looked it up. You said they idle fine, then that is probably not the problem seeing how that circuit(s) appears to be operating properly? So when they are both idling along fine, you put the port engine in gear and only that one stalls correct? Then the same for the other engine. Is it weird that both would have the same problem (AIC or whatever) at the same time? Is there something that runs both engines that could affect them? Bad ground somewhere? Btw, your setup.....wow.

yes

Start both and they idle fine. Increase rpm, no issue. Idle back down and put in gear, they die.

What are they idling at? Is this new or with the blower upgrade?

Idle is fine, can't remember exact idle but seems to operating normal. Motors/blowers have 36hrs. Completely rebuilt 2021.

is this happening first time out this year ? scan it and report back