Why does fuel pressure drops when electric fan turns on
Hey guys, how's everyone doing? I am in need of some help here. It all started last June 2004. When my electric fan comes on, my fuel pressure begins to drop down. I have a very mild small block 350. It has an Edelbrock 1406 carb, mild cam, headers, high flow water pump, 180 thermostat, and a heavy duty radiator. I have installed a Carter electric fuel pump rated at 7 psi as well as a Holley mechanical fuel pump and pressure regulator.
I have flushed the radiator, adjusted the timing as well as readjusted the carb. I have also tried water wetter as well as the 40 below stuff. All is well as the motor begins to warm up until the electric fan comes on. The liquid filled pressure regulator shows 7 psi, then as the temp reaches 180 and the fan comes on, the pressure begins to drop down around 2-4 psi at idle. The pressure use to drop down to zero and it would bog down and die. The temperature stays constant between 180-200. The engine runs smooth and doesn't smoke, or burn any oil. The motor only has 498 miles on it. I haven't driven it since last June so I don't know how it will do while being driven. Can someone please help me out here. I would like to drive it before I am too old to see. Oh by the way it is a 57 Chevy Step-side. Thanks to all in advance.