If I read correctly, you put your hand up to the intake, blocked it, and it stalled? On a good running engine, that SHOULDN'T happen, unless you block it completely with a solid object, air tight. Which, to mention, you should never do. Thats way too much vacuum pressure in the intake...no idea what could happen, but don't go there.
Heres a list of things to do in this situation, I see you've done some, so disregard those.
Clean MAF (with designated MAF cleaner or alcohol ONLY)
Check ignition coil resistance
Check fuel pressure
Replace fuel filter
Replace Spark Plugs
Replace Spark Wires
Seafoam into intake
Seafoam into fuel tank
and how many miles are on this engine?