Have you checked to see if you are making fuel pressure at the fuel rail when you are actually cranking the engine?
My own Dak (5.9) went through a period in its life when it would INTERMITTENTLY shut down & start back up. Then intermittent devolved to terminal. It turned out to be the PCM, but that is not to say that I am suggesting to automatically suspect your PCM. I have typed out the troubleshooting sequence I used on numerous threads, so let me see if I can find one of them & I will copy & paste:
On mine ('03), these are the checks that can be made, & I will paraphrase: "test for battery voltage to the coil by disconnecting the connector from the coil & using a MM to check for volts at the dark green/orange wire with the ignition ON.
THis is an edit: if the PCM does not recieve a valid signal from the crank and cam position sensors within TWO seconds of turning key to on, it will deenergise the ASD relay and you won't read voltage until you crank the engine or repeat the on to off sequence with the key. Meaning you either need to have your voltmeter set up & ready to go and where you can see it when you turn the key on, or you will need an assistant.
No voltage=bad ASD relay.
If volts: use the ohm-meter function of your MM & check primary & 2condary resistance of the coil. My Haynes lists 0.95 to 1.20 ohms & 11,300 to 13,300 ohms respectively, but I believe Haynes is giving me inaccurate specs on that.
If coil ohms out good: check the trigger signal from the PCM. Using an LED test light (inexpensive from Advance or the like) back probe the coil driver terminal (black/gray wire) & check for a flashing light as an assistant cranks the engine.
If no flash: then check the operation of the cam position sensor & the crank position sensor, and their associated circuits (those are the two sensors I alluded to earlier in this reply).
If those sensors test good: send the PCM out to be diagnosed."
My own Dak (5.9) went through a period in its life when it would INTERMITTENTLY shut down & start back up. Then intermittent devolved to terminal. It turned out to be the PCM, but that is not to say that I am suggesting to automatically suspect your PCM. I have typed out the troubleshooting sequence I used on numerous threads, so let me see if I can find one of them & I will copy & paste:
On mine ('03), these are the checks that can be made, & I will paraphrase: "test for battery voltage to the coil by disconnecting the connector from the coil & using a MM to check for volts at the dark green/orange wire with the ignition ON.
THis is an edit: if the PCM does not recieve a valid signal from the crank and cam position sensors within TWO seconds of turning key to on, it will deenergise the ASD relay and you won't read voltage until you crank the engine or repeat the on to off sequence with the key. Meaning you either need to have your voltmeter set up & ready to go and where you can see it when you turn the key on, or you will need an assistant.
No voltage=bad ASD relay.
If volts: use the ohm-meter function of your MM & check primary & 2condary resistance of the coil. My Haynes lists 0.95 to 1.20 ohms & 11,300 to 13,300 ohms respectively, but I believe Haynes is giving me inaccurate specs on that.
If coil ohms out good: check the trigger signal from the PCM. Using an LED test light (inexpensive from Advance or the like) back probe the coil driver terminal (black/gray wire) & check for a flashing light as an assistant cranks the engine.
If no flash: then check the operation of the cam position sensor & the crank position sensor, and their associated circuits (those are the two sensors I alluded to earlier in this reply).
If those sensors test good: send the PCM out to be diagnosed."
