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Fuel pump issue


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So, I'm going to address the electrical problem with the fuel pump on my newly-acquired 79 EA71 4WD wagon first.

 

Raven told me that the fuel pump needs a pulsating +12v current, not a constant one. I'm thinking that the fuel pump on these cars might be like a cylindrical compression type of pump, instead of a rotary pump like the newer cars. Please correct me if I'm wrong.

 

It definitely needs a pulsating current though, as I can get the engine to start if I rapidly touch a +12v wire to the fuel pump for a couple seconds and then crank it over. It will then die of course, but doing that procedure puts enough fuel in the carb that will allow it to start and run for a few seconds.

 

I haven't tested it, but I'm pretty sure Raven said the wire coming off the harness will only give a constant +12v current and not a pulsating one.

 

So where should I look for a solenoid or what-have-you that pulsates the +12v current like that? And where can I get a replacement part?

 

Thanks in advance!

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There was a factory service manual on eBay just this past few days....for $0.99 ! They have a $5 handling fee and were willing to use MediaMail so the price would have been under $10 total.

 

I passed on it because I got too busy and really don't need another one.

 

Might be still on,might be re-listed,but still go get one.

 

The f/p is the cylindrical type,not rotary.

 

Some things to consider for the f/p:

connections,especially grounds

 

plunger and plunger tube can get dirty,and can be cleaned.

 

Are you sure you have a good voltage regulator?Good alternator diode?

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This is the only one I see, and it's 83, so it won't help me. If my Haynes is right, 83 is definitely different from 79.

 

I was kinda just throwing the cylindrical thing out there, but I guess I was right! Cool!

 

Do these cars have external voltage regulators, or are they in the alternator like I'm used to?

 

Much, much thanks for your help Moosens. I will see what I can find out!

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About the manual I was talking about,it ended.But the person is still selling other items.eBay name is "Vermont_Ham"

Check their other item (Honda Gold Wing I'm sure is still listed) and contact them thru that listing.Tell them your friend said (you do consider me a friend,right? :lol: ) that they offered to ship it cheap thru MediaMail.They said they wanted $5 for handling....still,a great deal,probably around $10-12 total.You won't find them much cheaper than that.

 

External V/R is located up by the battery.Mounted to the side,up near the top.

 

Diode assy is covered by that plastic cover you're talking about on your alternator.

 

Happy to help.;)

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You guys rule! Plain and simple! :banana:

 

I shot vermont_ham an email, let's see what he says.

 

I checked my catalogues today, and there are two different alternators listed, depending on VIN. There is one with a small diode on top of the alternator like you said, and there is one inside the alternator that's a bit bigger. You seem pretty sure though that it's the former. I'll double-check it tomorrow.

 

Unfortunately, the former-mentioned diode is in the neighborhood of $75 list (!), and there aren't any in the country. But I'll try ordering it and see what happens. I might get lucky.

 

Edit: So I think I have the internal diode :( I don't see the external one on mine, at least not the way it looks in the catalogue.

 

000_0864.JPG

 

But I'm not gonna jump to conclusions just yet. I'm gonna test everything first before I condemn it.

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Hold on,you have an internal diode in the alternator but not an internal voltage regulator.

 

The one with the internal v/r is for Californication cars,which use the electronic ignition (not points and condensor).This is alt. does not have the plastic cover.

 

Yours is a "49 States" car.You need the alt. with the diode (black plastic cover).

 

 

Dude,email me or PM as you need to.I have factory manuals,service and parts.So if that dealership (?) you work at tossed them,or never had them,I can help you out.

 

If you have the manuals at work copy them,at least the pages you kind of need right now.Catch me on a good night and I'll be able to take the time for scanning for ya,should you need them.

 

You get that service manual and you'll be WELL down the road to success.

 

Also,keep in mind that Subaru of America themselves have recently told us that they have been unable to resource many parts for their own assistance in the restoration of Ronald Raygun's Brat.Get what you can while you can.No need to go nuts for common replacement part though.There's tons of Alternators,Starters,Brakes,Ignition parts,Struts,etc. that show up on eBay constantly.

 

And,should I give you part numbers,always be sure to let the person doing any research know that you have the original part number.P/N's got updated over the years.

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Bah, I forgot to post the other picture.

 

I understand the difference between the diode and the V/R. The V/R, if I follow you correctly is circled in red in this pic:

000_0862.JPG

 

I got a super-quick response from vermont_ham, and I've already paid for the FSM, so it should be on its way soon.

 

I'm very appreciative of your help moosens, but if it's cool with you, I'd like to post this stuff on the open forum for everyone's information, in case someone else has the same question.

 

I know the parts thing is gonna be rough... Some stuff is still available (apparently, all the clutch-related stuff for EA71's is still available in SOA warehouses), but a lot of stuff isn't of course. I do have access to all part numbers and their respective supercessions, it's just the parts themselves I'm gonna have trouble with :-\

 

What about aftermarket stuff? How good are Advance, Autozone, etc?

 

As always, thanks so much for the help from everyone. It will pay off when you see this car on the road again! :cool:

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Sure,post here,either way works for me.

 

Yup,that's the v/r.

 

Supercessions,yeah,like that...;)

 

The big stores don't help 70's owners too much,but always try.It can get real frustrating dealing with dorks who have to go by what the computer shows them.They'll only get you the high replacement parts anyways,which you can score off of eBay much cheaper.But hey,if you have the time to try go ahead and see what they can dig up.I tend to think they won't offer an real gems though.

 

Beck Arnley parts are fine for your Subaru in most cases.

 

Cheers!

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So I found a place here locally in town who specializes in alternators and starters and electrical parts in general. I was actually delivering a Mazda part to them and decided to ask.

 

Their computer showed one alternator in stock for a 79 (!), and they even had a picture in their system, which is definitely the right one (internal diode). They even said they could likely find a V/R too, not to mention that they'd gladly test both.

 

If I get some time, I might take my old stuff off and have them test it to see if they're good.

 

There might be hope!

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The power to the fuel pump is supplied by the voltage reg. Frequently that portion fails and you get no power to the fuel pump. I'd try replacing the voltage reg first. Check your charge power at the battery with the car about 1500 rpms. You should have greater than 12 volts....like up to 14 volts. That would mean your alternator is OK.

 

Todd

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I just checked the SOA V/R part number and it's no good :(

 

So what I'm gonna try to do is see if I can find a solenoid or something that will pulsate the +12v current from the battery, and then hotwire it straight to the battery, so the fuel pump will operate and I can have the car running. Then I can check voltage and all that fun stuff. If that doesn't happen, I'll just take the V/R off and have it tested.

 

Thanks man! Also, if you come across another EA71 tranny, lemme know! :D

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You can hook the fuel pump to a regular 12 volt line. The pump is pressure sensitive and only pumps when the pressure between the carb and the pump drops. (During operation and fuel burn)

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  • 4 weeks later...

So I was playing around after work today (when I should have been doing homework :lol: )...

 

I hooked my remote jump starter up, took a +12v line and popped the fuel pump with it a couple times, then left it hooked up to the fuel pump. I started the car, and after some reluctance, it fired up, and went to about 3k rpm! It sounded sweet! :banana:

 

... then it died about 5 seconds later :(.

 

You all know better than I do, you say that leaving a direct +12v current on the fuel pump will allow it to run continuously. But it seems to me like it needs the relay to alternate current so it keeps cycling and thusly, continue pumping fuel.

 

Now that I've gotten it to do this, do you guys still think it's a fuel pump relay, or could I potentially have a carb issue?

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Well, it seems to me like the float is stuck open.

 

Played around with it some more yesterday, and I can get the engine to run for about 10 seconds if I keep the throttle wide open. Then it dies. I'm fairly sure it's flooding, because the exhaust is REALLY strong and smells a little of unburnt fuel. So I'm guessing (with my lack of carb experience) that the float is stuck open and letting the carb flood.

 

Anyone have any more insight on that?

 

All the aftermarket chains sell carb kits and say they have them readily available, and since I now know the VR/fuel pump relay is bad, I checked those aftermarket and they're available too. So once I pull the engine I'll probably get to rebuilding the carb. I just need to identify what type of carb it is.

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Actually, I know it's a 79, I know it's a 1600 engine, and I know it's a 49-states model, that's not high-altitude, so yeah, that should tell me enough to get the right carb kit.

 

Duh. :banghead:

 

I'll pull the air cleaner off soon and take some pics of it.

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