Pressure problem
Pressure problem Recently a friend had a fuel pump replaced cause the old one was reading in the lower 50's, it was absolutely trashed. It was replaced with a Walbro 255 by a shop, and everything went smoothly. It read the normal 58 PSI and went a little higher at times. It started dropping to 50 PSI now, at times. And when the lights or turn signals are on, the voltage lowers about 4 PSI. It's kind of weird. Also, the car holds no pressure at the "Schrader valve". THe regulator looks fine, and the pump is new... any ideas as to what can be causing the lower PSI? Fuel filter has been changed also...
Originally Posted by DaGeneral
...the voltage lowers about 4 PSI. It's kind of weird. Also, the car holds no pressure at the "Schrader valve"...
When you say the car holds no pressure, do you mean that it bleeds off immediately, or that it reads zero at the valve?
Walbro pumps do not have a check valve to hold pressure after the pump is shut off it may leak back to tank. But it also sounds like you have another issue. Do you have a hotwire kit on the pump it pulls more amps than factory and needs upgraded wiring, and check the hose attaching the pump to the sender on the inside very common for it to come loose or leak.
Nate
Nate
We've been contemplating buying that hotwire kit, but its kind of expensive. Pretty sure the pump just isn't getting enough voltage. Is that going to be the only alternative?
Im going through somewhat the same thing. I have the right fuel pressure but somthing mysteriously is not letting the fuel deliver. Ive replaced my fuel pump, filter, alternator (thinking it was voltage issues), checked EVERY ground, checked voltage at the pump but my car is still stupid lean at wot and it all happend when I swapped a new set of ported heads on 
