Another thought.You said there is 12V to the injectors and you have injector pulse to ground from thu the ECM. Did you load the circuits with a light bulb? If a wire gets corroded it may show 12V on a meter but won't have the amperage to get the job done.

The only light I used other then my meter was a test light. I haven’t used a noid tester on it. But test light lit up for 12v that goes to the injectors, and we also used it to test to see if it was getting a pulse and it was.

Can you borrow his scanner and monitor data. Or back probe the tps sensor connector terminal C- DK BLU wire and ground. Thats the signal wire to the ecm. About .5V Closed throttle and about 4.5 V WOT. Terminal A is 5V reference and Terminal B is Ground.

I’ll have to probe it and check. If it’* not responding that way then the sensor is bad which could be causing the injectors not to fire? My father and I are stumped on this lol. We’ve ran out of ideas as to what it could be.

The poppets will not open even if they are triggered (pulse) when the fuel pressure is even a couple pounds low.

Pressure holds at 60-61psi during crank. Should be enough to make them fire.

If they sit for a long while the poppets will get frozen and need to be shocked free. I know they used a nitrogen charge to free them up.

Some Nubee/ Novice and perhaps al little dumb ideas / suggestions. Not sure what that truck has. Perhaps it is a Throttle body injection instead of a fuel rail type injection. Would it be a dumb idea to take the fuel rail off or injectors out and while pressurized with fuel and just hanging in a 5 gallon bucket watch to see are they puttting out any fuel when pulsing when cranking. If you haven't already done it then clean the injectors off the vehicle. I cleaned by by clamping them in a piece of water hose and spraying in some injector or Carb cleaner and then hooking the other end of the hose to my Air compressor and pulsing them with 12 volts to spray. Could there be some some residual trash in the fuel line that gradually clog them during the first 1500 miles. Also, doing the bucket test would give you a chance to compare a new injector against the ones you are using ot see if there is any difference. I like the idea about the Throttle position sensor setting being in flood mode but, the fact that the truck got gradually worse seems to perhaps indicate there might have been a gradual clogging of the injectors that got worse over time but, doesn't fully explain getting zero fuel now unless a lot of stuff broke free suddenly and clogged the fuel line near the injectors. Can you flush the fuel line just before the injectors and add an additional filter just before the injectors after you clean the injectors and flush the fuel line. Could the LTFT be set so lean that the pulse width is too narrow of a pulse when cranking and would resetting the OBD2 reset to a normal pulse time? Could you borrow a Ocilloscope to check the pulse width?

It'* a Vortek engine with the CSI fuel system.

You have brand new poppets in this?