To get the nomenclature correct, that is called the ignition coil and has nothing to do with what I was mentioning.
The circuit opening relay (COR) has 2 coils that close the contact inside the relay. The primary coil (the one that activates first) is fired from the starter circuit while the starter is cranking the engine to supply the initial start up fuel pressure. The secondary coil (the one that activates second) is fired when the flap inside the AFM opens when the engine begins to suck air. This keeps the fuel pump running while the engine is running.
What's happening on your truck is the primary coil is firing from the starter circuit, and the engine stalls after 2 or 3 seconds after you release the key from the START position because the fuel pump is being shut down. That could be simply because the intake plenum is torn after the AFM allowing unmetered air to bypass the AFM, therefore not opening the flap in the AFM, which in turn shuts down the fuel pump.
I would remove the intake plenum and carefully look for cracks in the bellows sections. Below is an old picture of the plenum in my 91 FJ80 that would stall out in reverse due to the engine shifting on the mounts.
View attachment 3489007
View attachment 3489011
