Fuel Pump issues

[ajslacker]

I've been searching around the Forum for about a week trying to figure out my problem and I can't so I'm making a post for it. I have a 1985 Subaru Brat 3 speed automatic. I've been working on this thing for a year now and I have everything cleaned up I just got new brakes for it all I need to do is fix this fuel issue and it will be roadworthy. So, I have a Spectra fuel pump that I got off of RockAuto, I actually have two. I was able to drive it around some when I spliced  into the fuel pump wires bringing the positive up to the ignition coil and grounding it on the chassis. but the wire was extremely long and just hanging down and if I hit a bump or turned to hard the car would cut off because it wasn't getting fuel anymore. So I got rid of that and I spliced again back into the stock wires. So basically I'm back at square one. So my question is what could be causing it not to come on? I know it's not coming on because the Spectra fuel pump makes a clicking noise while it's working. Is there fuel pump relay somewhere? Or is there a fuel pump fuse somewhere? I'm just really fed up because I've been stuck on the same issue for 6 months. Any advice or wiring diagrams or anything would be helpful. 

Sorry for the long post

Thanks.

Edited July 15, 2018 by ajslacker

[ajslacker]

Just to clarify when I had it wired to the ignition coil I can hear it clicking when it was on. That's why I know it's not on now.

[el_freddo]

There should be a little black box near the steering column area. This will be an 8 wire plug from memory.

This box is the fuel cut out relay if it can't detect ignition pulses from the coil.  Either remove it and loop two wires together (can't remember which ones now sorry) to run pump whenever ignition is ON or reace it and hope the second unit is good.

Cheers

Bennie

[DaveT]

I would need a factory service manual schematic to try to troubleshoot.  I only have 86 and up. 

[ajslacker]

My windshield used to leak before I got it resealed. I believe it leaked water on to the FPCU. I did the old trick of putting it in rice and it dried out. I thought it worked after that but I guess there is know way of knowing. So if anyone knows which wires to splice into to bypass it, I will do that tomorrow.

[DaveT]

IF the FPCU was powered while wet, especially with water that came through a rusty area, it will need to be cleaned washed and dried before it can even be troubleshot.  water with ions conducts.  If there was voltage between 2 pins for any length of time, corrosion [electrolysis] happens.   Not in minutes, but longer = worse.  Even without power, the contamination could cause malfunction.

Bypass for testing, for sure.

It is good to have something kill the fuel pump in the event of an accident that shuts down the engine.

 

 

[ajslacker]

If I bypass it and it does actually work then I will probably put one of those aftermarket ones that you can wire in and do that but either way I need to figure out which wires are used to bypass it so I can test it in the first place. So I will research as much as possible to figure out which wires are which.

[ajslacker]

I bypassed the fuel pump control unit by putting a wire with two little connectors on it between the blue and red wire and the large black wire. I'm assuming it's the 12 volt wire. it does stay on for the ignition but that's all I wanted this is perfect thank you to all that helped.