Howdy,
Basically I have a 3.9L MPFI EA, 3sp auto, just put in an AU headgasket.

In neutral (Park or Reverse) The car idles fine (nice and smooth) but when rpm is applied (say 2000rpm) and held then once the throttle is lifted the rpm will dropped quite quickly and the car will stall.

Also if the car is put in gear, the rpm will drop quick and stall, with no extra rpm needing to be applied...

Any ideas, MAP sensor?, Neutral Safety Switch?, Just need to teach the ECU?

Cheers,
TB