[Capri306]

Try backing the TPS voltage down to 0.90-0.95V. It really doesn't make a difference whether it's 0.99 or 0.95V over time anyway. The computer will learn, but the 1.0V barrier should not be crossed. You could have a voltage drop in the very leads you're using to measure the voltage, so it's just plain "safer" to go lower.

The other thing I've seen is the computer does have a problem regulating idle if the ignition timing is too advanced. The supposed "Mass-Air Idle Problem" was cured for me by backing the timing off a couple degrees (to 12BTDC). If you really know an EEC's programming and how timing affects idle/throttle response, it does make perfect sense.