Did you check out the coolant temperature sensor? It's located on the thermostat housing, two wire sensor. Check it for continuity via DVOM (multimeter) and make sure one wire has 5 volts.

That's an easy first check, there are others

*edit Are you saying it runs without the MAS plugged in?

Have you checked all the electric plugs, make sure the cranksensor is connected.

is there any open holes behind the mas sensor, if so this could be part of your problem cause the mas meeter's the air that comes in anything coming in after it, will not be read. my 95 gst was doing this i had a few vacuum leaks and boost leaks, i sealed them off and it runs like gold now

sounds like a problem i had with my stock n/t. mines started running rich then died then didn't wanna start, so i figured it flooded out so i took an air hose & blew air down the intake in an attempt to evaporate some of the fuel, then tried starting it again but still nothing so i unplugged the maf & tried again, started for a sec the flooded again so i started checking my coolant sensors my maf my fuel pump & finally after not having my car for two days i pulled my ecu & took the cover off to see if the board was fried & sure 'nuff, i had 3 small burnt spots & noticed a couple of corrosion spots from leaky capacitors. put a new ecu in & ran like a charm ever since.

so if its flooding w/ or w/o the maf plugged in & everything else checks out ok then i'd say pull that ecu & open it up look closely for dark brown/black spots on the board or green-ish yellow grain like particles near the capacitors.