[EarlySport]

There are boxes out there to convert an AFM to MAP ( speed density ). Look up MAP-ECU ( made in NZ ), or the old HKS-VPC. You can run ITB's with MAP, somewhat dependant on how big a cam you run. So yes, you can use MAP-ECU or similar to allow you to use ITB's and a stock motronic computer. MAP-ECU is laptop programmable to control the fuel curve.

Most ITB's though are run with big cams where the MAP signal is less than ideal, and hence they are mapped on throttle position only. I don't believe the factory motronic computer can be reprogrammed to function this way.

At the end of the day, an aftermarket computer with full programmability ( Haltech, Microtech, SDS etc ) are under $1K. When you consider you're going to have to re-map your motronic (or your $400 MAP-ECU box) dyno time won't be much different between the two solutions. All the factory motronic sensors can be used with an aftermarket ECU too. So in my mind it's really a no brainer to spend the extra $500 or so and go full aftermarket ECU.