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Guest Message by DevFuse

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EA 81 into RX

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5 replies to this topic

#1 Naked Buell

Naked Buell

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  • Evans, WA

Posted 25 February 2011 - 11:12 PM

So I finally got tired of the problematic EA 82 and pulled and put in my reliable EA 81. I swapped fuel pumps, fuel injection to the EA pump and I am not getting the pump to the carb. Does anyone know how to wire up the pump with the correct stock relay or I can wire my own relay, so it will start again and run as she did before????? Thanks Subie Bros. I appreciate the info. :-\

#2 MilesFox


    Catch this Fox!

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  • Madison/Milwaukee, WI

Posted 26 February 2011 - 12:39 AM

If it hepls you any, the black wire on the coil is positive, and the yellow wire is negative, same for the disty.

the fuel pump grounds to a common ground, and can be grounded to the body itself.

in the original design f the mpfi, the optical disty has a reluctor and 360 holes on a rotating plate, and sends a pulse signal to the ecu. The ecu in turn sends a signal to the ignition amplifier on the coil bracket. from here this transistor breaks a field winding circuit to induce inductance and produce a spark, like electronic breaker points.

also, the fuel pump should come on for 2 seconds when the car is first turned on. If you plug in the green test connectors under the dash, the fuel pump will cycle on and off when the key is in the run position.

if this works, this verifies the fueol pump is live with the relay, and the challenge will be tripping the relay. IF not, then your fuel pump is not getting volts, or ground

#3 Crazyeights



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  • Pacific Northwest

Posted 26 February 2011 - 04:28 AM

You could wire in a fuel pump impact switch (might be called an inertia switch) from an 80's or 90's Ford for safety in the event of an accident. They are usually somewhere in the trunk. Very cheap in the junkyard.

#4 Gloyale


    It's a sickness

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  • Corvallis, OR PNW

Posted 26 February 2011 - 06:32 PM

Find the Fuel pump relay, and I.D the Ignition switched 12v and the fuel pump 12v out.

Get the FPCU and the wiring pigtail from a carbed car. ("rev sensor" 5 wires, mounted above the hood release)

IIRC, these are the colors, using the pigtail, splice:

Black wire to ground.

Blue to 12v from Ig power wire to the OE relay.

Yellow to coil Neg (-)

Blue/black stripe to Fuel pump output wire on OE relay.

IIRC, the other wire from that unit supplys 12v to choke and bowl vent in the OE configuration. You may or may not want to wire it up that way.

#5 MilesFox


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Posted 27 February 2011 - 11:33 AM

I would like to see your finished project!

did you know that an ea82 water pump will fit on an ea81 motor? it does, but the belt alignment will be half a width offsed from the crank. You can retrofit the ea82 anciliaries to the ea81 motors to match the belt alignment to the wp, but the crank will still be slightly offset. Plus you an use the clutch fan for reliability.

I mention this because this will allow you to use the ea82 radiator, lower hose, and ea82 water pipe. I had a working example of this with an ea81 in an 88 dl with 3at

it's amazing how far you can mix and match a subaru across several generations of design

the ea82 pitch bar mount also swaps onto the ea81 block

the ea82 flywheel bolts up, but you have to grind part of the bellhousing away at the bottom corners.

#6 capn_r


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Posted 27 February 2011 - 11:45 AM

If you do use an EA82 flywheel be sure to transfer the ignition timing mark locations onto it from the EA81.

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