So I have been trying to help out my friend with his 03 MM. He puts it away in the winter time and starts it up occasionally during the winter months. This year when he took it out it wouldn’t start. When he finally did it ran rough and wouldn’t idle. He took it to a shop and was told the IAC wasn’t working properly. I got him an IAC from ford, installed it and it fired right up but soon after died. I checked the plugs and changed a few COPs, changed fuel filter then ran a fuel injector kit on it. Once again it fired right up, then died. I pulled a code from it P0511, the IAC faulty circuit . I thought maybe a bad connection and told him to put some dielectric grease on the connection. He called me later that night and said it still won’t idle or run well. Any info would be greatly appreciated. Thanks.