IAC Questions

Disconnecting the MAF has nothing to do with the IAC . It just shows that the MAF isn't doing its job properly.

The IAC isn't mechanically connected to the TPS. Changing the IAC does nothing to change the TPS setting. When you adjust the throttle stop screw under the throttle body, that changes the TPS reading. So any adjustment of the throttle stop screw requires a TPS check and possible adjustment.

Here's a book that will get you started with how the Ford electronic engine control or "computer" works.

Ford Fuel Injection & Electronic Engine Control 1988-1993 by Charles Probst :ISBN 0-8376-0301-3.

It's about $25 from Borders.com see http://www.amazon.com/ . Select boo...very good, and I found it to be very helpful.