1993 S-10 Blazer PROBLEMS!!!

[Armista]

I first apologize for the length of this description but I am now lost on what to do next.

Application:

1993 S-10 Blazer 4x4 4.3L W no mods

128 K miles
Recent repairs:
CMFI
EXHAUST
Tune Up
Fuel Pump
Fuel Filter

The truck died while coming to a stop once two months ago. I thought I was low on gas because I was close to empty if not fuming and was hard stopping. The problem subsided for about 4-6 weeks then it came back although it did not die at every stop. I began dropping the transmission into neutral and braking with my left foot why depressing the accelerator to keep it running. I was lost so I took it to a shop they found the vacuum line at the back of the manifold disconnected. From the schematic this goes to the MAP sensor so I thought that it was possibly the problem although I thought it was weird that there was no check engine light message. Anyhow that seemed to fix the problem for two weeks or so no its back. I checked the history codes and only get 12 flashing which means there are none stored. This model year (im sure others too) allows you to enter into an "active feedback mode" when diagnosing. This is done by starting the truck and then jumping across terminals A and B on the plug. The CEL will begin to flash quickly while in open loop, once the O2 sensor warms up and enters closed loop the CEL will flash once a second if normal or be on continously if running rich or off if lean. Well once I jumped the terminal the light began to flash then the engine sputtered and died. At this point it would not restart, so I again checked for codes and again none. I pulled the ECM fuse and waited a minute or so before reinstalling and then tried the process over. Again it died. Repeat. Short of just beginning to swap electrical components I don't know what to do next. Can the coil be weak? TPS sensor? Maybe cam or crank?

Any help from the members would be greatly appreciated.


-Jason