Truck cranks forever & sputters when letting off the key. I've improved the problem by either replacing or fiddling with ECU harness (converted to Mopar electronic ignition).
4 pin orange box I am assuming. I would jump 12V from the battery positive post to the blue yellow ECU terminal and to the coil positive primary terminal & seperately (on the ground side) from the ECU base to ground then crank it & see if it starts several times in a row & only let it run for several seconds if/when it does start to confirm or elim the coil/ECU are good tho they can be OK when cold then act up when hot but you did say this was an initial in the morning starting problem. then as said check voltage drops at the coil/ECU when cranking OR just start cleaning ALL terminals/connections especially the bulkhead & ign sw.
