I have a problem with fuel pressure dropping when I step on the gas. I have changed the fuel line, the fuel pressure regulator and the pump is reds xp double pumper. The new regulator worked well for about one day. Now the car bogs down and even stalls on hard acceleration. The fuel pressure gauge shows about a 4 psi drop in pressure then comes back to the original setting but does not increase. I am stumped because this worked well with the new regulator for a little while. Any suggestions?