Fuel pressure

I have a 2005 3.0 Vulcan. Just replaced fuel pump and filter over fall 2017 because I believe someone had put Acetone or some other liquid in gas tank. The only reason I figure this is when trying fill the tank at the gas station, when I took fuel cap off I could smell something of that particular nature coming from filler tube. Looked inside and filler neck looked like it had a white coating on top of the tube. Also, fuel would only pump something like ten seconds at a time then shut off. Few days later it just quit driving down the road. So I dropped tank, cleaned it, replaced pump and filter. When trying to start at first it would only stay running with pedal pumped but very rough run also excessive backfiring and fuel literally leaking out of tail pipe. Looked it over and concluded that it was getting too much fuel. Changed out the fuel rail sensor. New plugs, cleaned injectors, cleaned EGR, new air filter, started it. It ran but now when driving it it does not like to shift unless pedal is only 1/8 down no more or she will act like I am suffocating her. And then continue to act like that until I let it sit or it stalls altogether. (Even in the middle of a green light). I have learned to limp it to where I have to go by undoing the negative battery cable everywhere I go figuring it resets the computer to try again. It has worked so far, but cannot drive far. I thought maybe MAF but replaced it. Nothing different. Took it to a garage just to check fuel pressure only twenty pounds of pressure with key on. So do I need to replace the whole fuel pump again or could it be something more simple? Thanks sorry for the length. Also, when I replaced fuel pump the first time I am pretty sure I messed of one of the top vent things I pulled it out and the bottom cage thing snapped off. I stuck it back in the hole figuring it only served the purpose of a vent but not sure if that is contributing to the fact that there is little pressure.