February 10, 201412 yr Quick rundown of the Weber install and where I stand: 1986 GL wagon with freshly resealed EA82 new Weber 32/36 DGEV installed Vacuum consists of the usual - Distributor advance (single port) - Heater control - brake booster - 4wd vacuum line (I think?) Misc. - EGR & ASV disconnected. No quarter trick performed yet on ASV - Fuel return line & tank vent line disconnected at metal lines near firewall - Electric choke hooked up - Fuel mixture set at 2 turns out, idle speed set to 7-800 rpms Now for the problem...the car starts up quickly and idles.....sounds decent, BUT I'm getting a pretty constant popping back through the carb at idle & throughout the rpm range. I have not driven it yet just ran throttle up by hand. I just found a quote from GD that stated backfiring was usually an ASV or exhaust leak issue. On that note, my front cat on the y-pipe is fairly rotten and leaking so that may be it? A buddy suggested I was one tooth off which is easy to believe as I'm a noob with Soobs. As far as timing goes, the engine had the stock Hitachi on until this weekend. Perhaps it needs to be advanced a bit...... Any help is very much appreciated, I'm SO CLOSE with my first Subaru, reseal, engine R/R, etc. etc. As she sits.....
February 10, 201412 yr I Kindly suggest you to start by Moving Forward the Timing at the Distributor... Despite that my EA82's under the Hood Sticker said: 8º (+/- 2º) I discovered that it Runs way better between 18º and 22º ... I run it at 20º since many years ago. Also, do you know how big are the Weber's main Jets? Kind Regards.
February 10, 201412 yr Author Both 140 for the primary & secondary jets. I'll try & advance the timing tonight. Right now the distributor is set as far counter-clockwise as it will go (if that makes sense). I left it in the same spot as when I disassembled for the reseal. I was thinking perhaps that I may need to hook my return line back up. If so, where should I on the Weber?
February 10, 201412 yr Yes, seems like the Timing is Way off... 140 + 140 is the Usual jetting for EA82's ... I was thinking perhaps that I may need to hook my return line back up. If so, where should I on the Weber? Well, I kindly suggest you to not use the Return line on the Webers, it could cause gas starvation somehow... I left it unhooked since many years ago, on mine. If you still want to hook a return line, then You'll need to change the threaded fuel inlet pipe from the carb, for another one that has a smaller diameter return, in some kind of stretched "Y" shape. Kind Regards. Edited February 10, 201412 yr by Loyale 2.7 Turbo
February 10, 201412 yr Was it popping w/the Hitachi? Did you mess w/the timing/disty? Where do you have the vacuum advance hooked up? Can be many causes for an intake backfire,but,a lean mixture is very common. I`d be checking the base gaskets.
February 10, 201412 yr Author I ran the Hitachi for a very short time after I put the motor back in. It was leaking badly from the accelerator pump, etc. so I decided on the Weber swap vs rebuilding it. It popped a small amount but not nearly like the Weber is. Hard to compare b/c of the short time I ran it. I haven't messed with the distributor much at all. I've got the vacuum advance coming from the front right port on the Weber.
February 11, 201412 yr Author Ok, timed it to about 21-22-ish to run best but the popping still remains. If I tune it to 20 it doesn't want to idle. It's not really a backfire, just sounds like popcorn popping (my best explanation). Take away the popping and the motor sounds good. Here's a short, bad quality video of the sound
February 11, 201412 yr That is Weird!!! Are you sure that the Poppin' noise is comin' thru the Weber's Throat? All the Sparkplugs, Cables, etc... are in good shape? The Gasoline isn't very old? How does it accelerate?
February 11, 201412 yr Author Haha....sorry, I know the audio quality of that clip is crap. I decided on speed rather than quality so I could get it uploaded tonight. Yes I'm positive its coming thru the carb. All spark plugs, cables, etc are brand new. Gas is good, as I've replaced the gas tank and blown out the lines. The engine accelerates well, although the popping does get more intense higher in the rpm range. The car does have an immense exhaust leak, the bottom of the front cat is very rotten.
February 12, 201412 yr Author Well, after re-checking plugs, wires, disty, etc I decided to pull it out for a spin. It barely pulls itselfs while popping like mad. I think its safe to assume I've got the cams out of time.
February 13, 201412 yr Author Belts off, re-timed and back on.......no change. Could an exhaust leak really cause this much trouble?....because I'm nearing the end of my knowledge. Now plugging the EGR/ASV with quarters, is this done right at the outlets on the cylinder heads? Between plugging them and trailering it up to the exhaust shop to fix the front cat I'm not sure what else to do.
February 13, 201412 yr you should write your process fro timing timing it here. backfiring out the carb is generally a timing issue, so you may be missing a step or something. I think theres a second set of marks on the flywheel to set the time, not the timing marks like on another rig. you plug the ASV's with the quarter. it goes in the ASV valve itself at the metal hose connection. the EGR isn't a big deal unless its faulty, but generally disconnecting the vacuum supply will disable it. if it is leaky or something you can get a block off plate, pull the egr valve and weld it, or any number of things. I can't see either system having anything to do with your issue. Id definitely look to timing.
February 13, 201412 yr Author Yes, there are 2 different sets of marks on the flywheel. The first, a set of 3 lines that are for the valve/cam timing and then you have your TDC, etc marks for the ignition timing. After last night I am certain the valves are in time, so I'll re-do the distributor, plug wires, etc tonight. When I resealed this engine I took off the driver's side cam assembly & distributor off together. Perhaps the distributor position was indeed fouled up during that process. One thing I forgot, when we set the timing after the weber install, we forgot to unplug the vacuum advance from the disty per the underhood instructions. Last night when we started it up we found that pulling the advance hose off the disty caused the motor to die.
February 14, 201412 yr Author Another day, same problems. Fiddled with the distributor, plug wires, etc last night til I was blue in the face. Ran the ignition timing anywhere from 8-22ish degrees with it running best around 21-22. It still dies when the vacuum advance is pinched/removed from the distributor. The popping even manages to blow off the Heater control line I'm running off the intake. While reading this thread http://www.ultimatesubaru.org/forum/topic/75774-weber-install-backfire-from-intake/ it seems the same problem I'm running into. However, the thread died before any solution was posted. The more mechanics I talk to seem to think I've got a stuck or burned intake valve. I sincerely hope this isn't it.
February 15, 201412 yr idk, it all seems to point to a timing issue to me. if it were a burnt valve, then why now all of a sudden? its most likely going to be the systems you messed with recently. did you rotate the motor before installing the second belt? where did you buy the belts? its not unknown for people to sell you parts from a legacy or EA81 car (though not the EA81 in this case). perhaps you got the belts for a different suby? I have no idea if the EJ and EA belts are similar, but if they are close and one is longer or shorter… just throwing darts at the board with that last one. I can't say from my chair of course, but the most likely culprit of a backfire out of the carb is timing, and since you just messed with the timing then its even more likely. might check your coolant. the base gasket on the weber may be allowing a crap ton of coolant into the manifold. useful trick for vacuum leaks is to put your hand over the carb. if you got the mother off all vacuum leaks the car will still attempt to run with the top of the car mostly blocked off.
February 15, 201412 yr Thinking I would start it up then pull/replace plug wires to find which cylinder is causing it to pop. Then double check that the plug wires are indeed on the correct plug. If the plug wires are correct, I would pull the cam cover off and check valve operation. It may be that a cam follower has fallen out. If the exhaust valve can't open, you will get a pop thru intake when intake valve opens.
February 16, 201412 yr Firing order is 1324 arranged like this when looking from front. 2--4 1--3 Set timing belts to the 3 hash marks....not the 0 tdc. Also, it wouldn't hurt to plug the large tube that comes off the side of the EGR vavle. That guy can be a nasty Vac leak.
February 17, 201412 yr This is great advise: ...it wouldn't hurt to plug the large tube that comes off the side of the EGR vavle. That guy can be a nasty Vac leak. ... double check that the plug wires are indeed on the correct plug... But if everything is alright (Timing, Plugs, Wires, no vacuum leaks) let me tell you that once I saw an EA82 doing the same: Popping thru the Carburator, and after checking timing & Wires, the culprit was the Carburetor itself... Somehow, I'm starting to think that your Weber might be inadequately assembled ... Kind Regards. Edited February 17, 201412 yr by Loyale 2.7 Turbo
February 22, 201412 yr Just curious.........is the Weber a real Weber that was made in Spain or a counterfeit knock-off? How old is the catalytic converter? Results of a compression test?
February 22, 201412 yr Just curious.........is the Weber a real Weber that was made in Spain or a counterfeit knock-off? How old is the catalytic converter? Results of a compression test? What is a counterfeit knock-off?
February 22, 201412 yr I've seen 32/36 Webers that looks very close to the European ones, but their box says: E.M.P.I. (in the good quality imitations) and other ones that don't say anything in their boxes, nor in the metal casting ... Perhaps he's refering to this last ones with pretty bad quality for sure. Kind Regards.
February 22, 201412 yr I have the same problem with putting a new weber on my 1979 brat. not sure what to do. it started fine for a little and then now when I start it and try to give it gas, it just sucks air and backfires. can't find any vacuum leaks or anything. I know I do need a new exhaust system badly but don't know what to get or use or where or what or how or parts? good luck, post if you figure anything out to solve prob?
February 22, 201412 yr Yes, there are 2 different sets of marks on the flywheel. The first, a set of 3 lines that are for the valve/cam timing and then you have your TDC, etc marks for the ignition timing. After last night I am certain the valves are in time, Did you rotate the crank between installing each belt? It's needed. I didn't here you mention it. When properly timed, with the crank at the center of the 3 belt timing lines the dots on the cams should be 1 straight up, and the other straight down. On TDC #1 compression, they should be passenger: 45 degrees up and out, Drivers: 45 degrees down and out. Or like 10:30 and 4:30 to use the clock reference.
February 22, 201412 yr Here is a link to Weber production/history: http://www.jameng.com/news/20/What-is-a-Genuine-Weber.html I bought a RedLine Weber kit from Carbs Unlimited. It is marked "W", made in Spain and has a white choke housing. BTW, jeffrodta11, if you saw your shadow on Feb. 2nd, you will have 6 more weeks of rough Weber operation.........................
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