86/87 Carb parts ID and stuff

[3crows]

I'm trying to eliminate the mystery of what these things are and what they do and if they can be disconnected or eliminated to possibly improve the performance. The Hitachi I have on my '86' is new and was originally bought for my '87'. When installing it on the '86' I found that the elect. connection on the carb has 4 prongs and the wire harness on the '86' only has 3. So I took the solenoids off the old '86' carb and put them on the new '87' carb because I didn't know what to do with the extra wire that goes to the solenoid on the lefl side of the carb I have marked F.  I've had this carb for several years in a box unused so I'm not going to buy a Weber for another $300. As stated in many threads, the vacuum hoses and such are plum confusing and and possibly unnecessary since I don't have to do the emission test. I'd like to remove as many as possible so I've also marked several things on the carb and engine that I don't know what they do or are there for. In another post I said that after hooking everything up it wouldn't idle smoothly, It wouldn't stay running at 800 RPMs and RPMs had to be around 950 to 1200 and vacillated between these two to idle. It revs up fine but comes back down slowly, about 3 or 4 seconds. If I were diagnosing this at first I would say a vacuum leak somewhere but after spraying starting fluid all around in there and not having any increase in RPMs I'm baffled at this point. The timing is about 8 to 10 btdc, a little hard to time with erratic  RPMs. I was also going to use a disty out of an '87' but found that the plugs from the '87' and the '86' are different and don't have the same number of wires either so it's the '86' disty with new cap and rotor and new NGK plugs.

So, can someone tell me what these things are for? Would be much appreciated.

And one other thing. There are 2 plastic cans, both on the passenger side, one on the fender well next to the carbon canister and one on the firewall, with hoses connected to them that go to the intake manifold. I couldn't get a good picture so didn't include it.

Chokes the brain!

And one more question. Is '87 the last year of carbed Subaru's?

Edited February 25, 2016 by 3crows

[machineit]

I have a shop manual for 85 to 87 gl, those have many vacume operations, many selinoids, many plug ins. I don't want to spenp $300 on little components to make a emission carb work, I had a Hitachi too.I New off the get go it would be problems, when I bought the car, disassembled, the guy said the carburetor had less than 6 hours use, however most of the components were gonw. My point is, the engine could not be tuned because of things being unhooked, plugged and obvisly not running the way it all was designed to do. I can take some pictures of the manuel to show the components that are required to make the Hitachi carb runable, however they are spendy as you know, yet will never be what you want. A few have told me that the secondary never had worked, most are running around with a one barrel carb. Let me know, I have been dealing with carbs for a minute, right now I have a 2 barrel Rochester on, it was bad at first, after making timing ajustments, a spacer, it seems great.I have a couple carbs, only into each $60 ready to go, if I get in gear and reassemble them, lol, willing to help out.

[3crows]

Thanks for the response machoneit. Since I'm pretty sure I've got the hoses hooked up right I'm just going to start plugging them one at a time and see if it runs better or worse since no one on my thread has offered any knowledge as to what this junk does or is for. Some of the hoses are supposed to have a restrictor in them and I may have left them out. There's a little plastic widget on one or two hoses about the size of the end of your index finger that acts like a diode for vacuum. Since I don't know what the hoses are there for I don't know if I have them facing the right way. ' Spect I'll have to figure it out myself. Trial and error, I suppose. Though most people don't like the Hitachi carb and talk up the Weber, seems there's plenty of people on the forum having trouble with tuning Webers too. For a little better response and about the same MPG, I'm not so sure it's worth $300 although it does make the engine look a lot more sanitary.

[firehawk618]

Thanks for the response machoneit. Since I'm pretty sure I've got the hoses hooked up right I'm just going to start plugging them one at a time and see if it runs better or worse since no one on my thread has offered any knowledge as to what this junk does or is for. Some of the hoses are supposed to have a restrictor in them and I may have left them out. There's a little plastic widget on one or two hoses about the size of the end of your index finger that acts like a diode for vacuum. Since I don't know what the hoses are there for I don't know if I have them facing the right way. ' Spect I'll have to figure it out myself. Trial and error, I suppose. Though most people don't like the Hitachi carb and talk up the Weber, seems there's plenty of people on the forum having trouble with tuning Webers too. For a little better response and about the same MPG, I'm not so sure it's worth $300 although it does make the engine look a lot more sanitary.

 

 

IMO you're on the right track.  One thing you can do is simply follow each line to see what it goes to.  If it end up going to a smog device you can cap it off and remove the device.  Just keep doing this until they're all gone.

 

I'm working on an 86 with that carb right now and the only vacuum line I have hooked up to the carburetor is the one that runs the choke pull off actuator.  I have it plugged straight into manifold vacuum.

Edited February 22, 2016 by firehawk618

[3crows]

In my pictures, the damits I have labeled E,D,C, you have capped? The one I have marked as K I believe to be the vent for the fuel bowel which goes to the carbon canister. Seems like I read on a thread that that has to be either left connected or just restricted some. Do you have that one capped also and no problems?

[firehawk618]

I don't want to lead you down the wrong path.

My car runs but runs like chit.  The carb has massive play in the throttle shaft.

I have a Weber due to be delivered tomorrow.

 

I came to the conclusion the shaft is allowing way too much vacuum for three reasons.

1. When I hold my hand over the top of the carb I can make it run pretty damned good.

 

2.  Spraying fluid at the shaft would cause it to run proper for about 3 seconds.

 

3.  The primary and secondary venturis appear to be spraying plenty of fuel.

 

In the past when I have smog deleted vacuum nightmare cars I just disconnected and capped off everything except the PCV and vacuum advance on the distributor and any choke pull offs if equipped.

If there were vacuum actuated HVAC then I would feed vacuum to that but the carb had virtually nothing plugged into it when I was done and they all ran fine.

Edited February 23, 2016 by firehawk618

[djellum]

Ive done a couple weber swaps and if you have a new hitachi id finish the full instal. Webers are fine and simple but the biggest benefit is replacing a worn carb with none worn one for cheaper. I wouldnt eliminate any of the hoses attached to the carb, almost none of them are truly emmisions related, they are there to make the carb work right.

 

 

First things first you need to make sure which hitachi you have. There are feedback and non feedback, and they are a little different ea81 vs ea82.

 

 

Its hard to see on my phone but i believe the bowl vent is the largest port on the upper right side of the first pic. Its simple to hook up, just hook it to the charcoal canister and supply proper vacuum to the canister, even if other stuff is plugged. The first widget is the thermo vacuum valve and will end up hooked to a few of the front ports (should be on the vacuum diagram sticker in the motor compartment).

 

 

The second plasric canister on the fender in the other pic is the anti afterfire valve. Id remove it. It is there to keep the engine from making poping noises while coasting off throttle. By now its probably failing and causing leaks. On that note spray this, the canisters, brake booster, etc for leaks.

 

All i got time for right now, you can find diagrams somewhere here

Edited February 24, 2016 by djellum

[3crows]

Just finished pulling the Hitachi off and putting on a Weber. End of problem!

[Loyale 2.7 Turbo]

Just finished pulling the Hitachi off and putting on a Weber. End of problem!

 

Share photos with us! 

 

Kind Regards.

[skishop69]

Even though you've installed the Weber, I'll say this so you know. The carb with the four prong connection is a computer controlled carb. Solenoid "F" is the mixture control solenoid. The two carbs are not interchangeable. You can put a non computer controlled carb on computer controlled vehicle, but not the other way around. If you do, it will run too rich and give you more grief with the emissions crap.

[AlcyoneSpiral]

Well done 3crows! I just pulled off my carb and intake on my EA82 to get some work done and took tonnes of photos to make sure I could put it all back together properly. I only just read this thread and would have offered the photos to you. Congrats on the Weber. I too hope to do that very soon. How did you go with the adaptor plate? Any photos? 

Edited November 19, 2016 by AlcyoneSpiral

[3crows]

Alcyone, I just stuck to the 6mm screws but I wrapped them with  a thin strip of shim material where they go through the bottom plate so they would be snug in the plate with a dab of locktite. Runs great but hard to start. Thing I was worried about, re drilling to 8mm, was that when you try to re drill a hole bigger it can wobble the bit and not drill a true center.

 

skishope, that may be what the problem was but I'm a Weber jock now. If I can just figure out the hard starting problem I'll be clam happy. Both Hitachi carbs looked identical. My Soob doesn't have a computer but it seems to me the new Hitachi had a 4 prong connector that didn't fit the socket in the wire harness so I took the plug off the old carb and put it on the new one. It was either 4 to 3 or 3 to 2. I'll have to check..

[3crows]

As far as the manifold goes, I screwed  machine screws with loktite into all the unused vacuum ports and plates over the EGR ports. What I did find out here lately, now that the weather is colder and you need to defrost the windshield, it wont work unless you maintain a vacuum line to that dammit thing on the passenger side firewall. Other than that, the only vacuum line you need is for the distributor advance. Damned if it don't look plum sanitary in there now! Not happy with the funky air filter but I just saw a neat setup on here making an adapter to fit the stock Soob air filter to the Weber. My next project.