Severe Stalling Problem

I have a 94 Chevy Blazer K1500 series, 5.7 liter 350. When my truck has warmed up and I take my foot off the gas pedal, my truck dies whether I am still moving or stopped. IF I try and restart it, it won't turn over. It is def not the battery, I checked my mapping, checked the EGI valve, all vaccum lines, changed the fuel pump and filter, along with a few other relays that I was given problem codes for. Pretty much, when my truck should just be idleing, my fuel injectors stop spraying. I have checked everything in the world for the last 38hrs and came up with a few problem codes, took care of all those and I still have the same problem. Any ides? I have been hearing something about an ignition switch? Suggestions please? If you can e-mail me that'd be great, [email protected]

BATTERY AND TERMINALS CHECKED
EGI CHECKED ALL VACCUM LINES CHECKED
FUEL PUMP, SCREEN, AND FILTER REPLACED
AIR FILTER REPLACED
GAS PRESSURE REGULATOR REPLACED
MAPING COMPONENT REPLACED
FUEL INJECTORS CLEANED

It won't turn over as in won't start, or won't turn over, as when you turn the key, nothing happens, no starter , nothing.

Check Engine Light? What codes?

Originally it wouldn't start, one of the first things I had tested was the OEM switch it came up good. Finally said fuck it, replaced the OEM today and tossed on some heatsink and she ran perfect. Thanks for the help guys.