93 Lumina Euro-no Spark Or Injector Pulse-puzzled

have a 93 Lumina Euro w/3.1 v6 in my shop that my Friend & I have been trying to fix for 4 days. We have no spark or injector pulse except once in a while after you stop cranking the engine the noid light will flash once or twice & coil packs will fire once .Now we have no fault codes,fuel pump runs & we have replaced , ECM ,ign mod,coil packs, crank sensor & ign switch.We have also ohmed out the injectors & checked them for short to ground . We checked the wires from crank sensor to ign mod & from ecm to injectors from ecm to ign mod. All grounds & hots at ecm are there ign mod power is present ..PLease help, as I have no clue where to go next!!!!!!!!!!thanks RodI

sounds like a security module issue with the VATS key system(if equipped). Try doing a key re-learn first (simplest and cheapest). If that doesn't work, then I'd suspect the security system.