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DCJ 306 Carb Questions


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Charcoal canister should be in the drivers side fender well, but you should be able to see it quite easily, it is a black canister with three vaccume lines going to it. Yours might not have one I'm unsure of the years they are used in. The fuel pumps burning out is mysterious, but if their getting hot that would suggest a blockage somewhere or the tank is unable to vent properly

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Yes, I have the Charcoal canister. I figured it was emissions control stuff so I haven't ever messed with it. I don't know about the blockage and I am not sure so I will find out Saturday when I give it a run again. I need to see if the fuel pump issue is the reason why the vehicle isn't accelerating. The cap and possible vapor lock is possible. It has never vented like that before so I am not sure what is going on. I have to disassemble my existing fuel pump to see what's up and maybe install the new one I have on the bench. Fingers crossed.

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I would say the problems are all pointing to a restriction, the problems with acceleration and other are probably because of lack of fuel, I would say all things are pointing to a bad evaporation system, running without the cap or with it loose will tell us a whole lot.

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When you change the fuel filters is there crap inside them?

 

I have a locking gas cap like we had in the 70's - early 80's when people would swipe gas regularly. That'll give you peace of mind from hater-folk.

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No crap inside them. Very clean. Just looked inside Tuesday when I was working on it. I am thinking a restricted or blocked jet. Here's the kicker - You can bring the RPMs up thru 3000 and she is fine. Runs great. Anything over 3000 it seems like she isn't getting gas and begins to drop off.

 

At idle you have to restict airflow into the top of the carb - That's a vacuum leak somewhere. I haven't been able to find it. I am not interested in tearing apart the carb. When you restrict the flow it runs great but at a higher RPM. Drops off at 1200 RPM and stalls from lack of fuel.

 

I have a friend and mechanic coming to look at her tomorrow. Possibly buying her from me for his kid.

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If that's the case you have no choice bot to remove the float chamber top and adjust the float. Don't sweat it. Breathe , take your time , and get it right. Of course you want to be careful bending the tab for adjustment .... you know that but we'll state it here for the next guy.

 

Me , I just did a "soft" rebuild using a complete kit but just not soaking it like I wish I could have. I rushed trying to just get the car ready for winter - which I basically succeded at - but I didn't take the time to go thru it after like a pro would. And now my accelerator pump boot is mashed and wizzing so I'm right next to you in the carb problem line.

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I have already removed the top of the carb, cleaned it out, replaced the top gasket, checked the float level, sprayed most of the parts & linkage with carb cleaner, installed new fuel line from the fire wall to the carb, and checked all of the vacuum lines. One of the bolts on the lower half of the carb on the intake manifold was not loose but I got a half turn on it with a 10mm wrench. It performs the same as what it did when it left me on the side of the highway. The fuel filter is less than 4 months old and I can see no dirt inside of it and there are no flow restriction through it.

 

If I have a vacuum leak, it's somewhere I can't find. I might even have a clogged jet. I did find dirt in the bowl. This might have entered from the previous bad gasket that was on the top and was not so great. I live on a dirt road. I hope I didn't lose an intake manifold gasket or the gasket between the carb and that manifold.

 

Now, I have not checked the "Charcoal canister" and I haven't looked at the vacuum advance hardware.

 

Again, she runs solid with an air intake restriction up through almost 3000 rpm. After that she begins to loose power and return to idle. Then she will spool back up to 3000 prm one you let the rpm's drop and you tap the accelerator pedal a few times.

 

It's either a vacuum leak or a fuel restriction. I have a mechanic headed over this afternoon to help diagnose.

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Check the fuel pressure, it should be 2-3 psi, I bet it'll be low, I don't think your carb is the problem, a real easy way to test if its your carb or a blocked line is to take the hose of the inlet side of the pump and connect a longer one going into a gas can see what happens, if it starts working then you know something is restricting flow. Unless of course the restriction is in between the pump and the carb.

Edited by mikaleda
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I sold the car to a mechanic this last weekend. I will be assisting him in getting it running again. At this point I have no Subaru, but I am looking at a Brat that's been sitting in a yard for a long time.

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