Numbchux Posted July 15, 2004 Share Posted July 15, 2004 At first I thought it was kind of funny, but now that my exhaust has broken off after the Y-pipe, and the backfires have started coming between every shift it's getting kind of old (like having a gun go off in the passenger seat with every shift). And I think my mileage is suffering as well. I was suspecting a vacuum leak before, could this be related? if so, where should I start in that nest of vacuum lines? if not, WHAT IS IT? I'd like to make this thing run better so any info/experience before I start taring into stuff would be much appreciated! -Chux Quote Link to comment Share on other sites More sharing options...
Caboobaroo Posted July 15, 2004 Share Posted July 15, 2004 well whatever it is, its putting unburned fuel into the exhaust causing it to backfire which would also make your mileage suck. I would check the timing and yes, a vacuum leak could cause it but lets start where it would be the easiest. So, check your timing, if thats not it, check your vacuum lines to see if you have a leak. Quote Link to comment Share on other sites More sharing options...
calebz Posted July 15, 2004 Share Posted July 15, 2004 The massive exhaust leak you have going on will cause it. Quote Link to comment Share on other sites More sharing options...
TomRhere Posted July 15, 2004 Share Posted July 15, 2004 I asked this question myself awhile back. If your y-pipe is broke before the cat, it will definetly be backfiring. It's caused by the Air Suction Valve(s) and the rest of that system. It adds air to the exhaust system to aide the cat in doing it's job. With the leak, it just helps make noise. I took the y-pipe and cat off of mine and ran duals, had a double barrel shotgun going off each time I shifted. Plug the hoses coming off the breather, going to the ASV, and you'll be quieter. Quote Link to comment Share on other sites More sharing options...
GeneralDisorder Posted July 15, 2004 Share Posted July 15, 2004 The ASV's on the EA82's are different, but on the EA81's I use quarters to block off the valves - the added air from the ASV system mixes with the unburnt fuel and ignites from the hot exhaust. You have a leaky exhaust basically, and if you want to fix it proper, then you should replace your y-pipe. After the y, you can have lots of leaks and it won't matter much. GD Quote Link to comment Share on other sites More sharing options...
MorganM Posted July 15, 2004 Share Posted July 15, 2004 The massive exhaust leak you have going on will cause it. Hahahaha thats one BIG exhuast leak Chux: if you want I could give you a hand and check it out. I'll PM you my number and just gimme a call. Quote Link to comment Share on other sites More sharing options...
archemitis Posted July 15, 2004 Share Posted July 15, 2004 if you like subarus, and your in minnesota, you gotta stop by my house sometime. im in uptown minneapolis. my ea82 carb did that for a year, before the timtnig belt broke, i kinda thought it had something to do with alot of slop on the belt. but the air suction valves sound suspect too. i got a welder!_! Quote Link to comment Share on other sites More sharing options...
Numbchux Posted July 16, 2004 Author Share Posted July 16, 2004 well, I checked the timing this morning, it was just shy of 10* (is there a way to put in a degree sign), so I adjusted it back to almost right on 8* and it seemed the same just for the around the block test drive (except for a bit more low end torque, nice) but this evening I went to a friends house and I think it was better, but maybe it was just a coincidence. I don't know, I'll check out the asv if I have time in the morn. Morgan, I'm pretty busy this weekend, but have nothing next week, when are you available (assuming I don't figure it out by then)? I'll give you a call and we'll see what we can find out. Quote Link to comment Share on other sites More sharing options...
archemitis Posted July 16, 2004 Share Posted July 16, 2004 you can take a hammer, and an anvil, and smash those air suction valves shut. or just plug the rubber hoses. or weld em shut. Quote Link to comment Share on other sites More sharing options...
Numbchux Posted July 16, 2004 Author Share Posted July 16, 2004 maybe I'll just stick with plugging the hoses. Usually when I use a hammer to try to fix something, more things end up broken -Chux Quote Link to comment Share on other sites More sharing options...
MorganM Posted July 16, 2004 Share Posted July 16, 2004 Ya plugging them is prolly the best solution. I had to use those lame spacers with the metal tubes coming out when I put an EA81 Y pipe on my EA82. It was pretty easy hammering them falt and welding them shut but they were off the vehicle. Kinda hard to hammer them flat when they are still in the car. Getting them off is a major PITA too. Have to use a big torx socket and a lot of elbow grease! Chekc your private messages too !_! Quote Link to comment Share on other sites More sharing options...
GeneralDisorder Posted July 16, 2004 Share Posted July 16, 2004 It's very simple - just unscrew the pipe, drop a quarter in there, and screw it back on. Done. Plugged. Getting them off is a PITA - best to use vice grips to loosen them as the torx bit tends to slip. (talking EA81 spacers here) If you can find the EA81 Hitachi Feedback cars, they had a blank spacer on one head.... GD Quote Link to comment Share on other sites More sharing options...
MorganM Posted July 16, 2004 Share Posted July 16, 2004 It's very simple - just unscrew the pipe, drop a quarter in there, and screw it back on. Done. Plugged. Getting them off is a PITA - best to use vice grips to loosen them as the torx bit tends to slip. (talking EA81 spacers here) If you can find the EA81 Hitachi Feedback cars, they had a blank spacer on one head.... GD Damn I'll have to find one of those hitatchi feedback cars and get the spacers. Torx kinda suck I had pretty good luck with using a torx socket adapter and a big breaker bar. A torch would have helped Quote Link to comment Share on other sites More sharing options...
Numbchux Posted July 17, 2004 Author Share Posted July 17, 2004 well, the ASV's are very much disabled, and it's better, but still not cured. I think that was just a "treat the symptom" fix, I'd rather get the unburned fuel out of the exhaust than just make less air for it to burn. Anyway, could it be just the extreme lack of backpressure? I knew Carbed motors ran better with backpressure (not like putting a coffee can on your honda) but I didn't think they'd try to blow themselves to bits. Also, my exhaust has been in this condition for more than a month now, and the backfiring was VERY rare until the beginning of this week (about the time I swamped it the last time , hmmmm...). Any other ideas?!? thanks for all the help -Chux Quote Link to comment Share on other sites More sharing options...
MorganM Posted July 17, 2004 Share Posted July 17, 2004 Still a few things to investigate tha tcould be culprits. As noted above exhuast leaks can cuase it, timing or slop in the distributor, slop in the timing belts, out of tune carb, who knows We should just hook up and hack it up! I'm sure some digging around will find the culprit. Arch would be a big help cuz he's worked a lot on carbed EA82s. I stick to the SPFI Quote Link to comment Share on other sites More sharing options...
Numbchux Posted July 18, 2004 Author Share Posted July 18, 2004 We should just hook up and hack it up! Deal, I'll call you on Monday or Tuesday. Quote Link to comment Share on other sites More sharing options...
GeneralDisorder Posted July 18, 2004 Share Posted July 18, 2004 Unburnt fuel is not the problem - leaks in your exhuast, and a crappy cat are. You won't get rid of the unburnt fuel - at least not with a Hitachi. My Brat had the exact same problem, and it was a bad cat, and exhaust leaks combined with the ASV's that caused it. Mine was so loud and hard, that it blew about 5 fist sized holes in the muffler. Once I repaired the leaks and replaced the cat (used y-pipe), it passed emmissions no problem. GD Quote Link to comment Share on other sites More sharing options...
Numbchux Posted July 18, 2004 Author Share Posted July 18, 2004 I will try a new Y-pipe, but like I said, the backfiring has only been a problem for about a week now, and the exhaust has been in this condition for almost two months!! Quote Link to comment Share on other sites More sharing options...
Numbchux Posted July 20, 2004 Author Share Posted July 20, 2004 Well, I was at my local Holiday Stationstore this morning getting some cool caffeine for my afternoon of replacing the front struts on my dad's caravan when I decided to try some sea foam and some carb cleaner. and it helped alot, it still goes off occasionally but not nearly as bad. I'm heading up to our lake cabin in Alexandria later this week and there's a good junkyard up there so I will be putting a Y-pipe on the list of things to look for. So maybe NEXT week some time morgan, though I think I can handle a Y-pipe swap, thanks anyway for the offer. -Chux Quote Link to comment Share on other sites More sharing options...
Numbchux Posted July 22, 2004 Author Share Posted July 22, 2004 Well, I bought a piece of pipe to slip over the two ends and reconnect the y-pipe to the muffler. Nothin, It's not making it to the end of the y-pipe. That will definately need to be delt with. Is there a way around the O2 Sensor? I may try to attach my dad's old EA81 Y-pipe that's in the rafters of the garage, but it doesn't have a place for the sensor. I'll give it a shot in the morning. Quote Link to comment Share on other sites More sharing options...
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