My 1981 Subaru GL Wagon 1.8L 2wd stopped running all of a sudden. After some diag work I found that I had spark to the plugs but no fuel to the carb. I put 12 volts to the pump and it turned on. After going to a Subaru dealer and getting what limited info they had on the car I tested the fuel pump circuit and found I was not getting voltage to the pump and there is 600 ohms resistance in the circuit. I was unable to locate a pump relay so I wired a switch to the pump to turn it on manually. Now I am getting less mpg than I was prior to the problem. Is the fuel pump turned on and off to get optimal mpg's? Any type of info would be appreciated.

Your 81 takes fuel pump voltage directly from the voltage regulator as a safety feature.Engine not running=no voltage=no fuel pump.

 

Alternator or regulator problems can result in no fuel pump on 81s.

There are two possibilities here - being an '81 I'm not sure what system it's using for fuel pump power. It could be powered off the voltage regulator or it could be powered by the fuel pump control unit (which is also it's relay). The things is - the choke is also powered by the FPCU and probably on the older models from the VR similar to the fuel pump. This insures that the choke only receives power when the engine is running and not with the ignition only turned on. The FPCU (which is definitely on the '82+ cars) would be located above the hood release cable bracket. It's a small, sqaure module with a 6 pin connector. The VR controlled cars have a different setup and I'm not familair with those as I have never owned one long enough to speak with experience about it. Anyway - hope that helps.... I beleive your problem stems from rerouting power to the fuel pump and neglecting to also power the choke - thus it's staying closed and causeing poor MPG.

 

GD