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need help with 86 brat fuel problem


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So it's been kind of an on going problem for a while, every time i start the car it idles really rough unless i pump the accelerator pedal a few times before hand, and when I restart the car hot if i run into a store or go to the gas station or something like that, the car lurches furiously unless i completely floor it.

  I've already had the carb rebuilt back in january and have only run the car on premium non ethanol fuel at the suggestion of the mechanic because the ethanol fuel breaks down the seals inside the carb. I recently spoke with a different mechanic in the area who was supposed to be the man to go to for older model subarus and he really wasn't that open to try and help, just gave me a price on what he thought it could be and mentioned that he was sick of having to deal with these old cars....... which was incredibly disheartening 

 

I know that problems like this are fairly common with older subes, in particular hitachi carburetors and I have done a decent amount of research; much thanks to the usmb, about alternatives including a weber swap and the spfi conversion.

 

My questions are as follows:

 

what are the pros and cons of a weber swap and what kind of performance can be expected on the highway if i go this way, fuel consumption, power and acceleration etc?

 

and would it be better to just go the route of the spfi set up? 

 

I'm also fairly new to mechanics everything i know i've learned from a haynes manual which has been really helpful for the basics but it kind of leaves me dead in the water when i come across problems that aren't mentioned in the book. I've gotten close to a thousand different suggestions from various people about what i should do and what might be wrong with it including guesses about the carb, disty, head gaskets, fuel lines, fuel filter and so on. I would really like to get an opinion from someone who knows what they're doing and maybe even come check it out in person and in the event that i do decide to go the route of the spfi would anybody be interested in helping me with the conversion? 

  

     thanks,

     Alex

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Did you replace both fuel filters?

The one up by the firewall drivers side & the one on the inside rail next to the fuel pump, which is just behind the bed.

 

If you did both of those then you're probably in the market for a Weber.

 

These carbs perform much better than the Crapitachi did or ever would, there are some that beg to differ though.

 

Webers are much easier to adjust and ect.

 

MPGs shouldn't change much. Your top end and start off the line will be the difference though, you will be amazed, or at least I was.

 

I can't speak of the SPFI swap though. Have not been there, I felt like it wasn't worth the trouble, finding a manifold and ect, to get it all set up.

Edited by Dinky26
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Being fairly new to mechanic work the Weber would be much easier and less hassle to install than FI. Most carb motors start better with a couple of pumps on the pedal if they have sat for a while. What kind of mechanic would rebuild your carb and leave you like that? There is some kind of exhaust gas recirculating valves that come off the bottom of the exhaust side of the heads. They are plumbed up to return to the carb. If those valves get stuck you will have much aggravation on your hands. If it is the same as my 87 Brat your Y-pipe bolts onto them. Maybe try bypassing those first. Mine were deleted when I installed a Weber many years ago. In hindsight I believe they may have been the cause of my crappy running and not the Hitachi. With that said the Weber was an improvement over the Hitachi even when it ran good. Plus it simplified under the hood work by cleaning up a lot of hoses and other mess.

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If you want to learn carbs you can either get a $30 rebuild kit for the Hitachi or a Weber for around $300.  The Weber will probably get around 2 mpg less than the Hitachi, and it's actually more difficult to tune than a Hitachi.  The advantage of the Weber is that you can get them new and they are a true progressive carb. 

 

The SPFI swap would be a superior and more permanent solution.  Since GeneralDisorder did the research, the mod, and write-up I would suggest talking to him since his shop (Superior Soobie and Import) is in Milwaukie.  It's not exactly close to Hood River, but it's not out of the question either.  He would be able to give you advice or you could hire him to do the swap for you if you wanted. 

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there is the basic tune up items to suspect first and if you've not replaced them, not a hard place to start with new spark plugs NGK BP6ES at 0.8mm gap, new HT leads, coil lead, check in coil tower for powdery corrosion, new cap and rotor. New air filter. While changing spark plugs do a compression test. Remove and clean out all the PCV hoses and PCV valve - it is a service item so too the little filter in the air cleaner housing. Then a spray in carby cleaner is worth a shot before putting a weber on....

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Alright cool thanks for the advice guys With that being said i'll probably go the route of the weber for now until i can gather the parts and tools needed for a potential fi swap down the road. Is there anything tricky that needs to be dealt with in the EGR delete or is it pretty strait forward? and is there any kind of weber swap guide around on here the hitches removals pretty strait forward but what will need to be done to convert the car to a weber?

 Thanks again for all the info its been really helpful 

   Alex

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