89 GT Fuel Pump Voltage
Question for you fox guys.
What is the voltage supposed to be at the pump when key is first turned to prime the pump?
I have a 70 Mustang with a 89 5.0 and 5 speed installed along with a Painless EFI harness. When I first turn the key to run the voltage is around 12 volts, tried starting it many times with no luck, then drops down and sits around 6.87 volts.
The fuel pump does kick on and run then shuts off like it's supposed to.
I did a fuel pressure check today and at first I got around 8 PSI. A few more prime cycles and it sat around 20 but then quickly dropped off. I ran straight 12 volts to the pump and it held around 40psi but the car still wouldn't start. Removal of the 12 volts the pressure dropped to almost nothing. I have a new pump and pressure regulator on their way.
Any who, voltage at the pump when key first turned??
In memory of shelbycarz
Last edited by kakn; 08-25-2019 at 09:45 PM.