78 911 sc Fuel pump

[gshase]

78 SC does not want to start ....Good spark and intermittent power to fuel pump operations. The hot lead to the fuel pump is disconnected and hooked up to a multi meter. I was led to believe that the fuel pump would run constantly with the ignition switch in the on position. If I jump 87a to 30 on the FPR I get my 12 volts to fuel pump. I have 12 volts again when cranking. I do not have 12 volts with a fuel pump relay in place. I have 2 new red relays and have tried all of the black relays. Should there be 12 volts to the fuel pump with the ignition switch in the on position?

[boyt911sc]

Originally Posted by gshase

78 SC does not want to start ....Good spark and intermittent power to fuel pump operations. The hot lead to the fuel pump is disconnected and hooked up to a multi meter. I was led to believe that the fuel pump would run constantly with the ignition switch in the on position. If I jump 78a to 30 on the FPR I get my 12 volts to fuel pump. I have 12 volts again when cranking. I do not have 12 volts with a fuel pump relay in place. I have 2 new red relays and have tried all of the black relays. Should there be 12 volts to the fuel pump with the ignition switch in the on position?

gshase,

There should be no power to terminal #30 (FP terminal) with the ignition switch @ ON/Run position unless terminal #85 is open (AFS switch). Or you have a defectibe FP relay that is stuck at NC (normally closed) terminals. For more comprehensive understanding how the FP relay and FP circuit work, search for DKLever48's post about FP relay. Everything you need to know and understand how to troubleshoot your current problem. Keep us posted.

Tony