My 05 5.3 (354k miles on engine) wouldn’t start a few weeks ago and it seemed like it was the spark plugs. I put new plugs and wires in the truck a few days later and it started right up like normal. I drove it to my friends house and back that night, all good. The next morning I get in it to get it inspected since the tags are 6 months expired and it wouldn’t start again. It was doing the same thing it was doing before I changed the plugs and wires. At this point it seems to me that it might be the fuel pump, starter, or coil packs. I’m not sure on any of those so I’m not going to buy the parts until I’m sure. I also put my code reader in it, but apparently it doesn’t work anymore. The video is what it’s doing now after I put the new spark plugs and wires in. It was doing that same thing before I put them in as well.