The truck uses the Malfunction Indicator Lamp (MIL) in the dash monitor panel to provide a means for determining if there are any Diagnostic Trouble Codes (DTC) stored in the ECM.
If you are successful in doing the accelerator pedal dance to set up the blink codes, you can count the blinks and figure out the 4 digit code number.
There is a diagnostic connector under the floor pan where a diagnostic reader can be connected to read stored codes and see "real time" problems.
If you are saying that there is not a Malfunction Indicator Lamp on the dash, how did you do the pedal dance you alluded to in your opening post?
The MIL should light up when you turn the key on and go out after the engine starts.
If the MIL does not burn when you turn the key on, that in itself is a defective condition, and must be fixed before doing anything else.
On your truck, look at the second light position to the right of the hour meter, the light that has an exclamation point (!) is the MIL.
That light should burn when the key is turned on and should go out after the engine is started.
If the light continues to burn after the engine starts, it is indicating that a defective condition still exists, or that a defective condition has caused a DTC to be stored in the ECM.
That light is what flashes to give you the blink codes for stored DTCs that the ECM may have.
The lift does not have a display on the dash to show any codes, all it has is a hr counter. Yes the screen was covered in grit. Tried cleaning the injector in case I let some of it through, still no luck starting.
You say you tried the pedal dance to reset the lift.
Were you actually able to put the ECM into blink code to show any stored DTCs?
Can you confirm that the MIL (check light) is actually working on the monitor?
Without knowing the answer to the above questions I would venture to guess that the main injector is clogged or defective.
You only stated that you cleaned the last chance screen. You did not say whether you found anything on the screen.
If you found any gritty material (loose like sand) and removed the screen while the injector holder was still mounted to the engine, you may have let some of that material get into the fuel passages below and subsequently migrated on into the injector.
Cleaning the main fuel injector with spray carb cleaner might yield an improvement in how it runs, however, I have found that simply cleaning out the injectors seldom.completely cures the issues