1991 Chevy S-10 My truck will crank then stut down after a

My truck has a 2.8L engine with the TBI fuel injection. My truck will crank but then shuts down after a few seconds. I replaced the fuel pump 3 months ago. Yesterday I replaced the fuel filter, and the fuel pressure regulator and the temperature coolant sensor. I have cleaned the EGR valve; I can push the diaphram in and out rather easily. If I unplug the temperature coolant sensor, the truck will crank and run like a new one for about 15-20 seconds and then shut down; then it will not crank unless I unhook the battery for 15 seconds and then it does the same thing as long as the temperature sensor is unplugged. I tried another temperature coolant sensor and it does the same thing.