both the same problem.would appear u have a vacum leak somewhere.guess would be in the line from the gearbox to the inlet manifold.auto boxes change in response to vacum load in manifold.u are losing the ",signal"which also explains the hunting as engine is drawing un meterd air through the leak causing a weak mixture.messing the computer up.leak has to be somewhere,may show up as a high pitched whistle at tickover that u can trace.hunt and find time.
caine, June 2008