intermittent miss/ stumble merkur

i know this isnt a 5.0, its a 2.3t, but same system basically.

my brothers merkur is really stumping me, weve been trying **** everyday but to no avail. ok one of the 2 stock pumps went bad, so he ditched the pusher pump and bought a 255lph high pressure walbro in-tank, and bypassed the stock pusher pump. now many many merkur guys do this with no problems, but this is when his problems began... coincidence i think. it runs fine for about 1 minute or less then has a stumble, just like it drops a cylinder, intermittently, that prevents acceleration... the problem goes on and off like a lightswitch being flicked, regardless of rpm, or boost level, even does it at idle at times
heres what we have tried so far:
(3) different new tps's
new pip sensor
new coolant sensor
swapped computers to la3 and swapped vams
new kirban afpr
new plugs
new wires
new cap&rotor
new iac
tried a new tfi
tried different o2 sensor

nothing stopped it


when i had the distributor out, i could move the shaft up and down about 1/4", maybe a problem...
timing has been checked and reset as well as fuel pressure.
i think we are gonna try a new distributor tomorrow or saturday along with ANOTHER tfi and maybe a different set of injectors and another t-bird rail with another pulse dampener on it


when i was datalogging with the tweecer, during the stumbling, o2 read rich, so im thinking ignition, but we changed everything except the coil, and thats either bad (no spark) or good i think...
even with the spout out, it still would intermittently stumble, so its not computer timing advance problem..

anyone have any ideas, this project is bothering me and i have finals, all i can think about is how this car is kicking my ass


help:SNSign:

thanks guys, it has no maf, it has a vam, swapped one with no results, swapped a tfi too, no results, datalogged and the narrowband goes rich when this problem happens...