Help with an 89 s10

I have an 89 s10 with a 2.5l tbi and 5 speed manual trans. The engine was recently rebuilt when I got it. It will not start and when it does it will only stay running for 10 - 15 seconds. I have replaced the starter, distributor cap, spark plugs and wires, fuel pump, fuel filter, fuel injector, hall effect switch. I am getting fuel through the injector and have sufficient fuel pressure and flow rate. I do not know wat to do next...any help will be greatly appreciated.

Not 100% sure but you might want to try the throttle position sensor. i had almost the same thing happen to a 91 jeep.