i mod'd my mini a lil bit by putting in a new intercooler/oil cooler / methanol injection [but ive made sure it's not runnin or even plugged in to see if it was a problem there and it wasnt..] . i have an IAC error ...i.e. car just starts then dies...poof! i also put in an oil pressure gauge [but used adptr. to keep old sensor online] a water temp gauge [a cut in onthing changed] and one of the boost adapters that u bolt on to run a boost gauge and a boost source to the methanol injection ] ----- anyone got any ideas whats going on????

 

Depending on the WMI system, you might have the sensors wired wrong, or it needs to be plugged in --- does it have a "fail-safe" circuit? You should be able to connect it, power it up, and test / adjust it, without running the engine, unless of course, you have a low-budget model, and / or no instructions.

 

You had a lot of the intake tract apart, even the smallest of air leaks on your car will cause poor idle, and stalling issues. Start with checking all your connections are clean and positive.

If you have the W/M kit piggy backed to sensors and it is either powered off or not powered at all that can cause issues if it isn't allowing the sensor value to pass through the W/M computer to the engine DME.