If either fpdm is unplugged the engine should still keep running, correct? My engine idles with 39 psi with the original fpdm (#1) unplugged and the GT500 fpdm (#2) plugged in. However, if I keep #1 fpdm plugged in and unplug #2, zero fuel pressure and the engine dies. I switched the fpdms around and it does the same. With Both #1 & #2 plugged in I measure 12v at the tank connections. My guess is a Dead pump?
Anybody?