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hello everyone, just got an 94 svx, and if i turn the key on and the fuel pump is connected, the orange/brown "RELAY 2M" buzzes and the fuel pump never runs. also the tach sits at 2k rpm. if i disconnect the relay, the tach drops. if i disconnect the fuel pump wire, the relay doesn't buzz and the tach sits at 0. i pulled the pump and connected it to a battery and it ran dry fine. after that i connected the pump back to the cars wiring and relay buzzes, ect. pump doesn't run, even dry.

 

 

HELP!

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i measured the ohms from the positive and neg of the fuel pump while it was disconnected and its reading 1.2 on the 200 scale and the pos and neg ohms of the cars wires is 150

 

volts is very low like .3

 

 

 

edit: when i unplug the fuel pump, and read the volts coming from the cars wires, its 6 volts.

 

is the pump bad?

Edited by K9WAGON

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the fuel pump relay wire voltages are

 

12v yellow

12v green

4-6v blue

 

and identical voltage at the blue wire on the pump.

 

bypassing the fuel pump modulator has no effect on the voltage of the blue wires (the short one inbetween the pump and relay in the diagram)

23924.jpg

Edited by K9WAGON
added picture

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Why are you looking at the main relay (orange/brown 2m) when the fuel pump relay is the silver one with the green plug in?

 

In the hundreds of fuel related diagnostics I have done on Subaru vehicles-old, new, etc.

 

Almost 0 failure rate of the actual relay unless its in a converted car (Ej22 swap, Vanagon conversion, etc).

Almost 99 percent failure of the fuel pump itself.

Maybe 1 percent is the fuel filter is completely clogged. Mostly old cars ---with a carburetor.

 

If the pump is bad-replace the strainer on the pump (usually required to keep the warranty from the manufacturer) and the fuel filter.

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the pump works, after i put 12 volts where it belongs on the blue wire, but now it seems to not be getting spark. :banghead:

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timing belt?

 

 

i wish, but no :( it turns over fine and sounds like its getting great compression on all 6, I'm not even sure if the injectors are firing. the fuel pump relay isn't working, I've tried 4 others and still the same. When I hook a volt meter to the blue wire on the FP relay(supposed to be switched 12v with the key) it has no voltage at all. if i power it with 12 volts the fuel pump kicks on.

 

the yellow wire thats connected to the relay is getting 12 volts. so is the black, and so is the green.

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I presume the blue wire ties power between the fuel pump relay and the pump and you are measuring a low voltage at the pump end of the wire, even with the pump disconnected. If you have 12 volts on both sides of the relay contacts when the relay is on then this means there is a problem with the blue wire. It has a high resistance along the line somewhere.

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stop check the brown ig relay for ig signal power this realy powers up first then feul pump check cp senser wires and cam senser wires if ecu dosent see cranking will not send signal to pump realay the svx had poor wireing on cp 1 and cp2 sensers had one with bad cam senser would not power pump or spark put in outback cam senser and fixed problem i have one here just did tranny on yesterday can check wires and voltages for you if needed

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