I do not whether the fuel pump will solve your problem, but I can tell you that I installed a walbro 255 on my GST with the re-wire, and no fuel pressure regulator, injectors, or anything yet, and there were no problems. Try putting the fuel pump in, and go from there.
My 255 pump is very very loud, and only about a year old. I recently rewired it, and the noise hasn't changed. I'm hoping a pump this new is not trying to die on me already. It seems to work fine other than the noise.
I recently got a ticket going 82 in a 65, which was considered reckless, because anything over 80 mph, or 20 over the speed limit is considered reckless endangerment in VA. I got a lawyer, because I did not want my insurance to drop me. I got the ticket reduced to speeding, and I also have to...