Why won't my s-10 blazer 4.3L TBI start?

well here's the tale: i was offroading with a friend after i had just done a fresh tune-up (spark plugs, wires, distributor cap/rotor, fuel filter, air filter - the whole shibang) well after about an hour or two of offroading we decided to call it quits for the night. mind you the truck ran wonderfully before and during the adventure. well i came to a stop, kicked it into neutral, and dropped it back into 2wd. the second i put it into gear again it stalled out. no big deal, i just turned it back on. Soon as i did i noticed my engine was incredibly sluggish. Accelerator pedal to the floor would give me little more than an idle and eventually it would build up in RPM's and speed. next morning i went to check on it and it had a loose spark plug wire. plugged it back and started it and it ran fine in idle so i let it run to check over the truck for any other signs of issues. within 10 minutes it stalled out and hasn't ran since. i've checked the fuel delivery its spitting fuel. spark plugs are good and spark. plenty of air and gas in the tank but she won't start. it turns over but the second you go to give it a little bit of gas via the pedal it bogs down to a halt and then eventually goes back to turning over normally until you give it more gas. i've changed out an injector (autozone only had one on hand for some reason) and it didn't make much difference. someone help me! thanks