Subaru_dude Posted February 28, 2013 Share Posted February 28, 2013 Here's the situation. 1984 Subaru DL 2wd 5spd 2door. Had EA71, swapped in an EA81 and de-smogged the feedback carb. Ran like it had a vacuum leak from day one so I stopped driving it. Fastforward to today. I've dropped a rebuilt Weber in there and replaced the crappy cardboard intake gaskets with legit Subaru intake gaskets. With the intake sitting on the heads there was no rock to the intake, so I know the surfaces are pretty well planed. I clean up the engine bay a bit and get the Weber adjusted according to what the Weber site says it should be to start off before final tune. Well, it's doing the exact same thing as before. Stumbling, high idle, seems to be running lean and while messing with the idle mixture it kept falling on its face. Was kinda hard to keep it running and play with mixture. Something else I have not done however is properly set the timing, used an EA82 flywheel. I'm wanting to say it's close BUT I could not say for sure because I can't get it running well enough to tune it by ear. So, I'm at a loss here. I know I should get a vacuum tester but I'm certain it's low on vacuum because the brakes barely want to work. But for the life of me, I CANNOT find ANY air leaks WHATSOEVER ANYWHERE on the carb or intake. I went through 2 cans of brake cleaner today trying to find a leak but NOTHING. What do I need to do, step by step, to figure out what is going on here? Could this be a sticking valve? Could the timing being off cause this? Exhaust leak at head? Fuel pressure being off? If I can't get this figured out I will have to part with it and I've put enough time and money into it that I really don't want to say goodbye to it just yet. This seems like a fixable problem but maybe I'm just overlooking something? It seems like I must be missing something right in front of my face and am just not capable of seeing it. If I could just get step by step instructions to track it down that would help me emmensely, I kinda don't know where to start. Thank you. Quote Link to comment Share on other sites More sharing options...
naru Posted February 28, 2013 Share Posted February 28, 2013 "desmogged the feedback carb" This sounds shakey. Test compression. Quote Link to comment Share on other sites More sharing options...
djellum Posted February 28, 2013 Share Posted February 28, 2013 have you pulled the plugs at all? they will tell you something without buying a tester, at least about fuel mix and such. my moneys on your timing. First id check your vacuum advance hose and make sure its hooked up to the proper port. if its hooked up to manifold vacuum your running way over advanced at idle. just pull the hose off of the distibutor and plug it with your finger. if the idle goes down reroute it. didnt the EA81 have a dual canister distributor? if so you need to make sure each hose is plumbed correctly. if that checks out take off the dist cap and see if the rotor will move by hand an inch or so and spring back, if it wont move or spring back it may be stuck at full advance. At this point you need a timing light and useable marks on the flywheel. maybe someone here knows how to make more marks on that one that will work. Quote Link to comment Share on other sites More sharing options...
Loyale 2.7 Turbo Posted February 28, 2013 Share Posted February 28, 2013 (edited) I need to know more Background history from that Weber carb you "Dropped" in that engine. Maybe it is Clogged / Dirty \ wrong jetted... or has worn internal gaskets. It is an Used Weber, isn't it? Even if it doesn't develop any vacuum leak, the carb itself could have an internal gasoline leak... So, if you don't know much about that weber, I kindly suggest you to dissasemble it to Clean the inner parts. Also to change the internal Gaskets... Good Luck! Kind Regards. Edited February 28, 2013 by Loyale 2.7 Turbo 1 Quote Link to comment Share on other sites More sharing options...
The Beast I Drive Posted February 28, 2013 Share Posted February 28, 2013 The vacuum diaphram in the brake booster could be bad, causing your undetectable vacuum leak. Try unhooking the booster hose and capping that port to see if it makes a difference. -Bill Quote Link to comment Share on other sites More sharing options...
ShawnW Posted February 28, 2013 Share Posted February 28, 2013 Did you have no brakes before the carb swaps? Did you put the 1 way valve in the brake booster line? Its more obvious on a GL than an Impreza but an Impreza I worked on a few years back had the hose backwards and like Bill said a bad diaphragm or the one way valve installed wrong would have symptoms like that. Did you have no brakes before the carb swaps? Quote Link to comment Share on other sites More sharing options...
Subaru_dude Posted February 28, 2013 Author Share Posted February 28, 2013 I had brakes before the swap, and I rebuilt the Weber and all the jets are correct and it's nice and clean. I only see one hose coming out of the vacuum advance on the distributor but I will definitely check to see if the rotor will move. Will also try plugging the brake booster hose. I have indeed pulled the plugs, they seem alright. They are Bosch so I will be swapping them for NGKs. Compression test... will do. Sounds like I need to pull it and stick the right flywheel on it so I can properly set timing. Thanks for the feedback guys, this is some good advice. Quote Link to comment Share on other sites More sharing options...
djellum Posted February 28, 2013 Share Posted February 28, 2013 what port on the carb is your vac advance hooked to? Quote Link to comment Share on other sites More sharing options...
ferox Posted February 28, 2013 Share Posted February 28, 2013 Everything you guys just mentioned was covered in the original thread for this vehicle. You should probably continue the old thread or link it to this one at a minimum. I also think the brake booster is a vacuum issue and the timing is the most fundamental setting for any engine, so you should probably get those sorted before asking what else it could be and having everyone post up a redundant thread. Quote Link to comment Share on other sites More sharing options...
Subaru_dude Posted February 28, 2013 Author Share Posted February 28, 2013 what port on the carb is your vac advance hooked to? It is hooked to the passenger side port. And the reason I didn't bother reviving the old thread is because it would have been redundant to do so. Like I already said, I will check the brake booster and insure timing is correct before bringing this up again. Quote Link to comment Share on other sites More sharing options...
Subaru_dude Posted March 31, 2013 Author Share Posted March 31, 2013 Okay I have gotten it running and tried to set the timing. (Don't ask me how, I had pulled the motor to replace the flywheel with the original and realized I didn't have a clutch for the EA81 flywheel so I just left the EA82 flywheel in there and threw it back in. Went to start it, and it cranked right up). So it has an EA82 flywheel and I have no idea if the timing marks on it are correct. I doubt they are because I had to drill out the holes to make it fit. So I did a google search and found that (in Australia at least) there is a mark on the crank pulley (in my case 2, 180 degrees from eachother) and these are supposed to be 8 deg btdc when lined up with the case halves, NOT TDC. I have no idea if this is true with the American market cars. I painted both my marks and went about timing it. It runs great if the mark is to the left about 2 inches, but as I turn the disty to the right to bring it to "8 deg btdc" it won't idle. It idles just fine if I turn it back to the left and the mark goes to the left, but it's not really driveable because it's still very gutless. Also tried moving the rotor in either direction a tooth and got kinda confused as to where my mark was supposed to be, but it's dark now and I'm pretty mentally drained and can't concentrate enough to keep track of what I'm doing. Any clues? If the disty is off some teeth would it do this? Quote Link to comment Share on other sites More sharing options...
TomRhere Posted March 31, 2013 Share Posted March 31, 2013 (edited) Your timing mark on the flywheel when running an EA82 flywheel on an EA81 engine needs to move 6* more advanced. IE; instead of using the 8* mark you need to use the 14* mark. I've ran a few EA81's with the EA82 flywheel, and they've all been that way. Just checked that again while putting the EA81back into my Wagon. It has the XT6 flywheel, but it's the same markings as the EA82's. Pull #1 plug, turn engine over by hand until you feel compression. Look into the plug hole and watch the piston, you can see when it gets to the top of it's stroke. Check the timing mark, should be at 6* BTDC instead of 0*. Turn engine to the 14* mark on the flywheel. Now, set your disty so rotor is pointing at #1 wire tower on the cap. It should start and run good at that setting. Webered EA8x engines do like a bit more advance than the stock carbs do. I've ran mine at 10*-12* (16*-18* with EA82 flywheel) with no spark knock. Edited March 31, 2013 by TomRhere 1 Quote Link to comment Share on other sites More sharing options...
Subaru_dude Posted April 2, 2013 Author Share Posted April 2, 2013 That's much better!!! However I still need to keep the mixture quite rich to run the way it SOUNDS like it should... next on the list is fuel pressure check. Thanks for the timing tutorial, it was very helpful. Quote Link to comment Share on other sites More sharing options...
TomRhere Posted April 2, 2013 Share Posted April 2, 2013 Glad the timing info helped. Tuning the carb is a "per vehicle/area" thing. Ran the same Weber on 3 different engines, each one wanted it set differently. Good settings should get you in the 28 MPG area at least. Quote Link to comment Share on other sites More sharing options...
silverback Posted April 3, 2013 Share Posted April 3, 2013 Redundant comment dept.: If the Weber has two ports on the front, the driver side is distributor vacuum advance port. It should be a larger diameter than the port on the passenger side. The smaller port, on the passenger side, is 'late vacuum port' for the EGR. Good luck Silverback Quote Link to comment Share on other sites More sharing options...
Subaru_dude Posted April 3, 2013 Author Share Posted April 3, 2013 Redundant comment dept.: If the Weber has two ports on the front, the driver side is distributor vacuum advance port. It should be a larger diameter than the port on the passenger side. The smaller port, on the passenger side, is 'late vacuum port' for the EGR. Good luck Silverback Thanks a bunch. I had no idea which one was the advance port. It's currently connected to the passenger side port. Quote Link to comment Share on other sites More sharing options...
ivans imports Posted April 3, 2013 Share Posted April 3, 2013 thoose cars had a buch of return to tank water seporators and tees i whould remove all that stuff make shure one line to carb one small line back to tank get all that extra junk outathere. On the last ea81 with ea82 flywheel i drilled a hole in bell to find tdc mark then could set timing was done with engine on ground and both flywheels back to back you could probly gess as i think tdc mark should be top center of bell or same as ea82. Feedback carb is real pos metering jet are you kiding me ! weber better way but better be good at tuning! Quote Link to comment Share on other sites More sharing options...
Subaru_dude Posted April 4, 2013 Author Share Posted April 4, 2013 thoose cars had a buch of return to tank water seporators and tees i whould remove all that stuff make shure one line to carb one small line back to tank get all that extra junk outathere. On the last ea81 with ea82 flywheel i drilled a hole in bell to find tdc mark then could set timing was done with engine on ground and both flywheels back to back you could probly gess as i think tdc mark should be top center of bell or same as ea82. Feedback carb is real pos metering jet are you kiding me ! weber better way but better be good at tuning! Yeah I noticed that T back near the fuel filter. Line comes out of the top of the filter down to a T thingy. I blocked one line but like you said, I think it would be much better to just have the one line running back to the tank. I'm gonna give it my best shot at tuning. Doesn't seem like it would be that hard, just have to get it idling and mess with the mixture and maybe get some jets to mess around with... Quote Link to comment Share on other sites More sharing options...
silverback Posted April 4, 2013 Share Posted April 4, 2013 The 'T' fitting is supply to the carb and the return to tank. The 'return to tank' should have a restriction orifice/smaller tube diameter. Do not restrict the fuel lines. Quote Link to comment Share on other sites More sharing options...
Subaru_dude Posted April 4, 2013 Author Share Posted April 4, 2013 The 'T' fitting is supply to the carb and the return to tank. The 'return to tank' should have a restriction orifice/smaller tube diameter. Do not restrict the fuel lines. I'm thinking of a different t-fitting I think... there's a fuel line coming into the filter from the pump and one right next it coming out of the filter straight to the carb. The line the fitting is on comes straight out of the top of the filter. About 8" long, goes to more of a Y than a T fitting. Quote Link to comment Share on other sites More sharing options...
silverback Posted April 5, 2013 Share Posted April 5, 2013 It is zero dark thirty right now, but I will try to send an image of the 'fitting' tomorrow evening. Quote Link to comment Share on other sites More sharing options...
ivans imports Posted April 5, 2013 Share Posted April 5, 2013 one line into carb one line back to tank with slight restirction on smaller line i like to use the factory ea81 carb inlet tube has a return line spigot built in put it inline even the return line prevents overpreshuring the carb float and neddle and allows the feul to return to tank to cool perventing feul heat soak. I remove all the water seporator lines and tees and just run a line from spigot on firewall to carb Quote Link to comment Share on other sites More sharing options...
silverback Posted April 6, 2013 Share Posted April 6, 2013 Something like this? I can't remember what this is off of. I think it was a feedback carb. The fitting attaches directly to the carb. The Hitachi that was on my EA 82 had two fittings on the carb. Upper one was for the return line and had a restriction orifice pressed into it. The orifice diameter is 0,7mm. The fitting below the return was supply and was unrestricted. Different carbs had separate ways to deal with back pressure and getting the excess fuel back to tank if that was required. Quote Link to comment Share on other sites More sharing options...
ivans imports Posted April 6, 2013 Share Posted April 6, 2013 i use the one on right the dubble one little one back to tank big one inlet Quote Link to comment Share on other sites More sharing options...
Subaru_dude Posted April 6, 2013 Author Share Posted April 6, 2013 fuel fitting_2.JPGfuel fitting_1.JPG Something like this? I can't remember what this is off of. I think it was a feedback carb. The fitting attaches directly to the carb. The Hitachi that was on my EA 82 had two fittings on the carb. Upper one was for the return line and had a restriction orifice pressed into it. The orifice diameter is 0,7mm. The fitting below the return was supply and was unrestricted. Different carbs had separate ways to deal with back pressure and getting the excess fuel back to tank if that was required. Yep, that's it!!! One "arm" goes to the fuel filter, the other I have plugged, and the bottom of the "y" goes to the tank I think. I'll have to get a fresh look at it when I get over there... but either way the car is running and played around with the tuning yesterday. I've gotta get a spark plug and wire, one of the wires was arcing straight to the exterior of the plug. I forget what the phenomenon is called (if it even has a name). I thought the stumble was it STILL running lean but after tuning it and driving it, I knew right then and there I was getting plenty of fuel. So I just stood there and listened to it run, and followed the sound to the #3 cylinder and sure enough that's what was causing the miss. With the hitachi it was running brutally lean, almost certainly because of the ultra grey used for intake gaskets causing a giant vacuum leak. I'm sure it wasn't quite in time either. Hopefully this is all straightened out... the only thing it needs is a working choke. This one is wore plumb out!!! Quote Link to comment Share on other sites More sharing options...
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