Combaticu5 Posted June 13, 2018 Share Posted June 13, 2018 Hey guys here with another hitachi carburetor quandary. I feel like I've been up and down these forums for fixing my cars running issue but I cant figure it out. I've got an 88 gl hatch with 150,000 miles that's been sitting for a few years. My Impreza was stolen so I decided to get this thing up and running. With just adding new gas and a battery it fired right up and ran decent. Because it sat for so long I went and changed the fuel filters. The distributor and cap are in great shape as well as wires and plugs. Because I was pretty sure the carb had never been removed i decided to rebuild it. I went through all the steps and got it back on in only a few days but now it's running rough. It won't idle unless its past 1200rmp and won't start without some gas pedal action. Also it seems to be misfiring quite bad. The spark plugs are gray implying its lean and the main jet sputters more than "jets." I'm not sure what to do. Here is a list of things I've tried. -vaccum leaks checked (none that I can find with propane) -adjusted the float to run more rich. (It just dies) -re-blewout all the vacuum lines and jets on the carb. -adjusted the timing to the FSM on each new adjustment. -and I've adjusted the idle mixture screw with nothing happening. This seems to be very odd to me. It should kill it if it's too rich or lean but I can screw it in all the way until it bottoms out our take it out completely with no difference. My suby has been down now for over a month with little to no change. I'll probably buy a weber conversion in the end but I want to understand this dreaded Hitachi and why it's not working. Please help! Link to comment Share on other sites More sharing options...
GeneralDisorder Posted June 13, 2018 Share Posted June 13, 2018 (edited) Carb is clapped out. Get a Weber. Understanding it isn't require. It's a carb - it works on venturi's, pressure differential, emulsion tubes, and jets (orifices) just like all the others. It's clapped out and no amount of futzing with it will magically turn it into a Weber. Don't waste your time. GD Edited June 13, 2018 by GeneralDisorder 2 Link to comment Share on other sites More sharing options...
Subasaurus Posted June 13, 2018 Share Posted June 13, 2018 the problem with those Hitachi Carbs is that they are made to work with the emission crap on it, as much as im an original freak at keeping a vehicle as original as possible, unfortunately after many, many months of tinkering with my Hitachi, i never could get it to work smoothly for more than 40minutes. i would go to walmart, and have to tune it again before leaving, i would leave work and time to tune it again, i would bottom out on the idle mixture at times just to get it to somewhat run right. all the calibrations shifted horribly on mine from day to day. the hardest thing about the whole conversion will be removing all the emission stuff, but after hours of doing the conversion on mine, first crank, and it started right up, with a growling sound too like the old carb was stealing so much power from it. $300 dollars is alittle harsh but its actually worth it at the end, i was a non believer at first, but i don't regret one bit of all the work i did to it. 2 Link to comment Share on other sites More sharing options...
Combaticu5 Posted June 13, 2018 Author Share Posted June 13, 2018 2 hours ago, GeneralDisorder said: Carb is clapped out. Get a Weber. Understanding it isn't require. It's a carb - it works on venturi's, pressure differential, emulsion tubes, and jets (orifices) just like all the others. It's clapped out and no amount of futzing with it will magically turn it into a Weber. Don't waste your time. GD 1 hour ago, Subasaurus said: the problem with those Hitachi Carbs is that they are made to work with the emission crap on it, as much as im an original freak at keeping a vehicle as original as possible, unfortunately after many, many months of tinkering with my Hitachi, i never could get it to work smoothly for more than 40minutes. i would go to walmart, and have to tune it again before leaving, i would leave work and time to tune it again, i would bottom out on the idle mixture at times just to get it to somewhat run right. all the calibrations shifted horribly on mine from day to day. the hardest thing about the whole conversion will be removing all the emission stuff, but after hours of doing the conversion on mine, first crank, and it started right up, with a growling sound too like the old carb was stealing so much power from it. $300 dollars is alittle harsh but its actually worth it at the end, i was a non believer at first, but i don't regret one bit of all the work i did to it. Thanks for your guys' input. I'm glad I'm not the only one having trouble with this. Hard to tell if people still have these problems because most posts are ancient. When you both put your weber's on did you follow any directions or just muscle through it? I'm hoping there is some diagrams or explanations out there to delete the emissions stuff. Link to comment Share on other sites More sharing options...
GeneralDisorder Posted June 14, 2018 Share Posted June 14, 2018 I've done about 40-50 of these swaps. Directions are not required. Neither is a kit. Get the carb, adapter, and low profile air filter. On the EA82 you will want a 60 or 65 idle jet. Rip off everything that isn't the manifold itself. Throw it all away. Run a vac line to the distributor. Tune idle mixture and speed. GD 2 Link to comment Share on other sites More sharing options...
wagons Posted June 15, 2018 Share Posted June 15, 2018 I've rebuilt these carbs so many times, and I found the easiest way to get them running perfect! Throw the SOB away! Follow exactly what GD says and never look back. No instructions are needed, if you need detailed ones follow jeszeks "ideas on swapping a Weber" thread. Buy a true made in Spain Weber, not an INTERCO Weber like I got ripped off on. It runs great, but let's face it, it's not a weber. One instruction I will say follow, plug carb warmer hole with jb weld aluminium/steel stick then mill it and the intake manifold flange flat. If you don't, leaks will find you fast. 1 Link to comment Share on other sites More sharing options...
Combaticu5 Posted June 15, 2018 Author Share Posted June 15, 2018 Thanks you guys for the help! A weber seems to be the way of the future. A couple more questions though. My engine is an ea81 so is a jet swap necessary like GD said for an ea82?. My altitude is around 3500ft if that matters lol. Also my carb has an 1/8th inch spacer between it and the manifold. Is it Stock? And should I leave it on with the weber adapter? I've heard some carbs use risers for better fuel mixture to the intake. Link to comment Share on other sites More sharing options...
Combaticu5 Posted June 18, 2018 Author Share Posted June 18, 2018 On 6/14/2018 at 8:32 PM, wagons said: I've rebuilt these carbs so many times, and I found the easiest way to get them running perfect! Throw the SOB away! Follow exactly what GD says and never look back. No instructions are needed, if you need detailed ones follow jeszeks "ideas on swapping a Weber" thread. Buy a true made in Spain Weber, not an INTERCO Weber like I got ripped off on. It runs great, but let's face it, it's not a weber. One instruction I will say follow, plug carb warmer hole with jb weld aluminium/steel stick then mill it and the intake manifold flange flat. If you don't, leaks will find you fast. On 6/13/2018 at 9:53 PM, GeneralDisorder said: I've done about 40-50 of these swaps. Directions are not required. Neither is a kit. Get the carb, adapter, and low profile air filter. On the EA82 you will want a 60 or 65 idle jet. Rip off everything that isn't the manifold itself. Throw it all away. Run a vac line to the distributor. Tune idle mixture and speed. GD Link to comment Share on other sites More sharing options...
SiriusBlack Posted July 5, 2020 Share Posted July 5, 2020 On 6/14/2018 at 10:32 PM, wagons said: I've rebuilt these carbs so many times, and I found the easiest way to get them running perfect! Throw the SOB away! Follow exactly what GD says and never look back. No instructions are needed, if you need detailed ones follow jeszeks "ideas on swapping a Weber" thread. Buy a true made in Spain Weber, not an INTERCO Weber like I got ripped off on. It runs great, but let's face it, it's not a weber. One instruction I will say follow, plug carb warmer hole with jb weld aluminium/steel stick then mill it and the intake manifold flange flat. If you don't, leaks will find you fast. I'm really not sure why soooo many people say to plug certain spots with JB weld. When I gave up on my hitachi after 2 rebuilds and did the weber conversion I did everything in a way that is not permanent, just in case I ever want to try putting it back to factory. Instead of putting JB weld in the coolant pool under the carb in the intake manifold, i covered it with the gasket that came with the adapter and slathered the thing in indian head gasket shelak. Then I went under the manifold and pulled and plugged the rubber line that feeds coolant to that passage. As for the carb warmer hole, I can't remember right now how I plugged that. As for the 2 silencers on either side of the engine i used some of the small metal disks that you punch out of a breaker box, slathered those in gasket shelak as well before putting them in and it works great. Link to comment Share on other sites More sharing options...
GeneralDisorder Posted July 5, 2020 Share Posted July 5, 2020 The redline adapter castings are not all exactly the same (because they are castings and castings shift). In addition the Subaru manifold is cast and the port is not always exactly the same. So telling people they won't have to plug the cooling port hole in the manifold is irresponsible - some will seal with the gasket and adapter and some certainly will not. I have seen both many times as I've likely done more of these swaps than anyone else on this board. So - notwithstanding your enormous statistical sampling of one whole car, please don't contradict my advice on the subject and you can also stop gravedigging posts from 2 years ago. GD Link to comment Share on other sites More sharing options...
SiriusBlack Posted July 5, 2020 Share Posted July 5, 2020 That's why I said that I also unhooked and plugged the rubber line to the coolant passage. I wasn't contradicting you, just offering another way I found to do it. Link to comment Share on other sites More sharing options...
GeneralDisorder Posted July 5, 2020 Share Posted July 5, 2020 8 minutes ago, SiriusBlack said: That's why I said that I also unhooked and plugged the rubber line to the coolant passage. I wasn't contradicting you, just offering another way I found to do it. The coolant passage is connected internally to the cross-over inside the casting of the manifold. Plugging the rubber line does NOT stop coolant flow to the bottom of the carb. You ARE contradicting me and my recommendation stands. In MANY cases people think they have plugged off the port with the adapter and gasket only to find their engine hydro locked days, weeks, or months later when the gasket blows out because the overlap between the manifold and adapter was 1/16" or less. To ensure a COMPLETE seal EVERY TIME the port must be welded up or blocked with epoxy. GD Link to comment Share on other sites More sharing options...
SiriusBlack Posted July 5, 2020 Share Posted July 5, 2020 @GeneralDisorder I took a much closer look, and see how it could fail in the future due to the gasket simply being unable to seal fully. As for the rubber line, I apparently never did pull and plug it like I thought. I've put around 4000 miles on mine with the gasket sealing that passage. I'm now trying to figure out another way to seal that passage in a non permanent way, as I am hell bent on being able to set this vehicle back to factory if need be. Thanks. Link to comment Share on other sites More sharing options...
GeneralDisorder Posted July 5, 2020 Share Posted July 5, 2020 Just now, SiriusBlack said: @GeneralDisorder I took a much closer look, and see how it could fail in the future due to the gasket simply being unable to seal fully. As for the rubber line, I apparently never did pull and plug it like I thought. I've put around 4000 miles on mine with the gasket sealing that passage. I'm now trying to figure out another way to seal that passage in a non permanent way, as I am hell bent on being able to set this vehicle back to factory if need be. Thanks. Why? You are already aware the Hitachi is garbage. Putting it back stock will never happen and even if it did you could just drill out the epoxy. But it won't - there's too many parts that can't be sourced for it to function in an "original" way. Vacuum valves, AAV's, and all the plumbing. Doubt it could be done and be functional without a pristine donor and if you had that.... just drive the donor. If you really want to plug it with a gasket, then TIG some additional material to the adapter, mill or block sand it flat, and cut a new gasket from a sheet of gasket material. GD Link to comment Share on other sites More sharing options...
Combaticu5 Posted July 6, 2020 Author Share Posted July 6, 2020 (edited) Hey GD, it's been a while and I replaced that old Hitachi for a weber and with a little work understanding the emission deletes it runs perfect! I'm so glad I did it. OEM is cool but not after messing with a Weber. I went with a manual choke and some days I question if auto. Would've been better. OUt the door like $400 with adapter hoses etc. Worth it. @GeneralDisorder Edited July 6, 2020 by Combaticu5 Link to comment Share on other sites More sharing options...
GeneralDisorder Posted July 6, 2020 Share Posted July 6, 2020 For sure. I prefer the electric choke. The manual is fun to play with but it gets old and one tends to forget about it. GD Link to comment Share on other sites More sharing options...
Combaticu5 Posted July 6, 2020 Author Share Posted July 6, 2020 @GeneralDisorder Yeah my suby sits for periods of time so it's like learning it all over again. Still fun though. Thanks for the advice that those old Hitachi's aren't worth messing with. I wanted to believe but after fussing with it for months it's not worth it. Haha Link to comment Share on other sites More sharing options...
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