86 MJ 2.5 won't idle

I recently purchased a pretty clean 86 comanche with the tbi 2.5, having been told by the previous owner that it needed a starter and a fuel pump. After replacing the starter, when turning the key to the on position you can hear the fuel pump prime, the truck would start, run for about a second and then die. After replacing the fuel pump the story is the same. After replacing the injector you can pump the throttle and get it to rev, but the pedal acts like a breaker switch that trips every time you press it. Holding the throttle will cause it to rev very briefly and then immediately die. Pulsing it will cause it to rev as long as you continue to pulse it. Occasionally it will catch and idle, although very poorly and infrequently. The fuel lines are clear, the pump and injector work as they should. Has anyone experienced this before? Any advice would be greatly appreciated.

Sounds like a plugged up fuel filter or a bad fuel pressure regulator. Pressure should be 14-15 psi. I think there is a test port on there somewhere?

I did not see a test port anywhere on the throttle body. If it helps, I took a video earlier of the truck. https://youtu.be/U0FgVEhXnKQ

Make sure your intake manifold bolts haven't loosened up and check the 2 vacuum lines to the intake manifold. They split.