93 S-10 Blazer 4.3L W Eng. runs bad

[rkwblzr]

After replacing the fuel pump, CPI fuel injectors and pump assembly, plugs, wires, cap, rotor button, most of the sensors (MAP, TPS, ICS, Oxygen, EGR and 1 or 2 others) the engine is hard to start and runs rough. It is running rich as indicated by smell and gas mileage. Jumping the ALDL gives only the 12 readout. If I reset the computer by disconnecting power it will run better and over time get progressively worse. My wife has had occasion where the brakes seem to fail. I suspected a vacuum leak and have searched throughly to no avail. Any ideas on what else to check or replace.