Because you needed to check the relay first lol.

Turn the key to run, -if you don't hear the pump charge the lines, you have to troubleshoot why. With the key in the run position and your absolutely sure the pump DID NOT charge the lines (you'll hear it, IF it does), -Crawl under and smack the tank with a hammer, - right in the center. Hit it hard just once, then listen for the pump. You'll hear it trying, if there's any life in it at all.

You have electrical, inertia and the relay. - It's the pump IMO. UNLESS you have a PATS issue. There's more than just one thing here it could be, your getting closer.

 

I'm not going to say I know what it is, but this sounds like an issue I was having a couple of months ago. I started a thread about it, dealership said I was getting the right pressure to the rail even though I saw it was wrong with my own gauge. Once I checked everything I could at the house I had to take it to the dealer.

 

It was the pump. 95 bucks and half a day later my truck runs great again.

Thanks for the help guys.