I had the same problem just recently. The Ecm controls yhe fuel delievery system, the injector pulse and the ignition timing. Just about everything. I had to replace my ecm. Ifound that Auto zone was pretty inexpensive. The use a company Called Cardone to rebuild the ecm. You must match the computer code to the new one for it to work properly. ECM -to-go is also good but a little more expensive.
You can get the truck to run if you cover the intake while cranking or use some starter fluid but you can only idle. Under acceleration it dies out. The fuel pump stayed on the entire time the ignition was turned on. I also found that by using a Code Scanner I was unable to retrieve any codes. Classic case of bad ECM. My check engine light was on the entire time.
Depending on what went bad in the ecm you maynot be able to get the truck to run.

CHECK THE ECM BEFORE THROWING ANYMORE PARTS AT THE TRUCK