ZX636RIDER03

so i attached the fuel pressure gauge today to the line and made it stick out the hood so i could see it. when i would turn the ignition key on, the pressure needle would barley move, after a couple turns of the ignition the pressure would finally rise. then i decided to take it for a spin at wot, so i would start at about 2500rpm in 2nd then i would punch it. as the rpm's would rise the fuel pressure would gradually drop to about 30-35psi and then it would hesitate again and then keep going to redline. so does this mean that the fuel pump cant keep up?

Injuneer

Could be the pump, could be the fuel pressure regulator. Unless you had the pressure gauge line pinched by the hood.

What did the gauge read at idle - 1) with the vacuum line attached to the FPR; 2) with the vacuum line removed? Did you take any pressure measurements at all without the hood closed on the gauge line?

Guest47904

Your fuel system appears to have a problem but it doesn't have to be the pump that is the cause.

Could be a filter issue or the sock in the tank. Could be the line from the pump to the tank connection is leaking. Could be a FPR problem.

Since you have an Aero FPR, I would suspect it first. SEVERAL people including me have had problems with it.