I reread the thread and all I can think of is check the sensors you have not replaced, look for an exhaust leak and a vacuum leak.

 

This can be very frustrating, having something "fixed", only to see it return. But, if you look at this thing logically, there is one thing you've done (twice now) that has worked, at least temporarily; and that is changing the fuel filter. Why would changing the filter have made a difference, except that it must be close to the cause of the problem. You may be inadvertently resetting or jarring something each time you change the filter.

Very important, is it possible that your tank is not being vented properly? When you repaired the leaking fitting on the fuel tank did you, by chance, block it off? If so, you might have caused a venting issue. If so, even though you replaced the filter, you're going to have problems keeping it running. Try leaving the fuel filler cap off (just while its on the driveway) and seeing if it takes the throttle better.

Keep at it, we'll figure this out.

 

Either that or you have alot of crud in the tank and continue to plug the filler. Have you dropped and inspected the tank?

 

I looked into the tank with a flashlight when I re-pulled the sending unit and everything looked nice and clean, additionally, the fuel sock on the pump and the cup that it sits in were all nice and clean. So I don't think it's crud.

I noticed when I pulled the filter yesterday that the filter was full of fuel, but only a few drops came out of either fuel line. I'm wondering if my fuel pump is either not running at all, or running weakly, it's brand new. I'd think the the fuel lines should be full of fuel, especially considering the this was literally 2 mins after I shut it off.

 

I'm not an expert on the fuel pump assembly, but most have a check valve that prevents the lines from emptying back into the tank when the pump is shut off. Sounds like your check valve is bad and letting the lines drain, although I don't think that would cause your stumbling problem.

Also, maybe the regulator has gone bad? Sorry, I don't recall did you place the entire assembly or just the pump? Might be worth it to put an external fuel pressure gauge on the fuel rail with an extension hose up to your cowl where you can see it (don't put it in the cab, don't want to catch you on fire), and monitor the fuel pressure when you're having problems.

 

So, today I pulled the supply line of the filter and had a buddy turn the key while I held the line in a bottle. It almost filled a 16 oz water bottle before he could turn the key back off. Next I put a clear filter in line before the main filter so I could see the fuel flow. Everything looked good, fuel didn't get drained out of the clear filter, so it looks like it's getting a steady flow.

Pulled the air cleaner and started it up. I'm not sure if you can see/hear in the video below, but the injectors were pushing fuel the whole time, even got a spray or two after the engine had stopped, or i should say, as it was stopping. Not really sure where else to look now. Send more like an air issue than fuel at this point, I know it's getting fuel, sense to be getting spark fine, it'll start right up every time.

https://goo.gl/photos/wjpeZEZnopx4BDr59

 

I think Robertmee's idea about you gluing the rollover valve blocking off the vent is very clever and probably right. IDK what I was hearing there but it seems like it starved itself to death.

 

The vent line wasn't what broke off, it was the supply line, vent hasn't been touched, the video was actually recorded with the gas cap off anyway, so it wouldn't matter if the vent was plugged.

I had pulled the cap to make sure the line wasn't pressurized while I added the clear filter.

 

Have you put a vacuum gauge on the manifold yet?

 

I plan to this weekend. It's still sitting in the parking lot at work, have to tow it back to the house.