Having a problem with two brand new fuel pumps not building pressure, one is an msd the other is an airtex. My problems are that with one end plugged with a fuel pressure gauge the other funneling fuel down they both only build 20 ish psi of pressure. They both should max out at 90 ish psi. I have also had both pumps on the car and they do the same thing, build 20 psi of pressure. Am i missing something? Car is also a 78 280z.