Blazer Forum - Chevy Blazer Forums - Engine won't stay on

I have a 92 Blazer K1500 with 350 TBI engine.

Going to start with initial problems since I bought it.
Before I did anything I did tune up by replacing the spark plugs, spark plug wires, distributor and rotor. Also replaced the coolant temp sensor near cylinder #1 since this was broken off and wire/connector was melted to the headers. So now truck seems to run more smoother and better so took it for test drive about 6 miles round trip and ran fine no problems. Well next day I decided to take it further to goto the store and get things and thats maybe 10 miles one way. Well I made it 8 of the 10 miles before engine gave me problems. Stopped at stop light when I pushed the pedal to go it sputtered and died. Couldn't get it started back up. Looked under hood and ended up full throttle open to get it on, stayed on once we started it. Well put it in drive and it died again. So checked the injectors and saw good spray, not drips. So eventually got it back on and rolled it down hill off the road and looked more.

I eventually disconnected one of the injectors on the TB and engine stayed on and could push pedal and wouldn't die, although it only had 1/2 power. Got it home and left it to cool off. On the ECM it only gives me error codes 12 (all good) and 15 (coolant temp sensor low). At this point I wanted to check the intake and took throttle body off and the gasket disintegrated. So bought a new rebuild kit and carb cleaner from auto store and rebuilt/cleaned the TBI. Also clean the IAC valve. So truck came back on, worked sat for while and put it in drive and reverse and pressed pedal and all was well after 15 mins of running. Took it around block to check it and seemed fine till I got it back to the garage where I let it sit couple more minutes and then it sputtered and died.

Round 3, Took my vacuum gauge and checked and it stayed at 15 with needle barely moving just above and below the 15 tick mark. Replaced the O2 sensor and fuel filter and now it won't stay on for no longer than 30 seconds. Someone suggest maybe the TPS sensor, says it should read 0.5v to 4.5v depending where pedal sits. Well took meter and measured a 0.48v throttle closed, 4.3v pedal to floor, close enough, stayed constant with several moves of pedal. At this point I noticed my injectors were not spraying but dripping so took it apart again and fuel lines to see if something got into it and didn't find anything and reinstalled it and now it sprays fine. Check the EGR valve and diaphragm seems to move easily.

Round 4 today. Checking some of the electrical again and still can't find anything, I have noticed today if I unplug the ECM it will turn truck on and 30 seconds later die and wouldn't be able to turn back on. So once truck cools off so I can pull new O2 sensor and reinstall old one without burning myself. Figured I would ask some pro's some pointers. I am leaning to either bad fuel pump (don't have test port and only place to get one for this is amazon) or bad ECM.