staticattic

i was having problems with my number 3 cylinder not firing, so i took that carb off, took it apart, cleaned it, pretuned it, and reattached it. then i set in to syncing the carbs. they were both dialed in perfectly. everything was working great with the exception of the constant popping sound that came every time i took my foot off the gas. the car would constantly pop anytime the engine was idling down. in idle, it sounded just fine. i was running an unbaffled stinger at the time. no matter how much tweaking (leaning it or running rich) i did with the carbs, i could never get rid of that popping. i eventually got it to stop the popping whenever i would blip the linkage bar, but when i got in to take it for a spin to the end of the street and back, it died as soon as the engine was under load. by that time, i was frustrated to the point that i felt like taking a hammer and smashing my engine to bits. after i walked around for a bit and took a break, when i came back, i decided the carbs were totally out of sync, so i pulled them both and set both of them back to the pretune settings. also, while stomping around in my garage, my baffle fell off a shelf and landed almost directly in front of me, like a message from the beetle gods. for grins and giggles, i re-installed the baffle. this go round, the car started and after some tweaking, i got the carbs back in sync. now, it will only lightly pop once during hard acceleration and only between 1st and 2nd. WTF? i don't understand what difference that baffle made. do carbs need a little back pressure to work better? or is it that with back pressure the carbs are a little more forgiving?   

Jeff
72 Super Beetle
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Ryan
Has nothing to do with the carbs.  An open exhaust design like a stinger lets fresh air into the exhaust system near the collector (hottest part).  It's actually kinda like an exhaust leak.  Fresh oxygen gets in, mixes with hot unburned fuel, and boom.
I've got to ask,,,,  you 'decided' your carbs were out of synch?  You do have a snail gauge right?  --Ryan

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staticattic
Sorry. I should have been more clear on that. Yes, I do have a snail gauge and yes, they were all moving the float to 7. After I calmed down to the point where I felt like working with them again, I decided I would start with a clean slate. So, I took both of them off and set them both back to pre-tune settings so as to have a baseline for which to build. By "out of sync", I guess I meant I didn't know what was where. Really, I think taking them both off and pre-tuning them again was overkill, but I wanted to start fresh.

They ran perfectly yesterday, no popping, perfect idle, smooth acceleration and cruising, etc. Today, it runs extremely rough and won't idle. According to the Weber book, one of the things I need to check is fuel starvation. I had a new fuel pump, but it was the wrong one, so I will get another one today. I am crossing my fingers that fixes the problem. Right now, the only time it will run smooth is when I am running wide open. Even cruising at 65mph it runs rough. From the book, it says the Main jets take over from the idles right around 45 - 55 mph. Being that it runs rough all the way through with the exception of wide open, I am focusing on the fuel pump. Especially since it was running great yesterday and both carbs have been removed and cleaned. I also took the fuel pump off before I realized I had the wrong new one. Maybe I shook some dirt loose that has now got back in the way? Thoughts?
Jeff
72 Super Beetle
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staticattic

So what is the secret for running stingers without the pop? When I had a stock 1600 with a single stock carb and an extractor with a stinger, no pops at all.

Jeff
72 Super Beetle
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staticattic

I took both carbs off yesterday and cleaned them out, AGAIN. That makes THREE times this week. I also replaced the fuel pump and the fuel filter. Yesterday after I finished, it ran flawlessly. Idled just fine, revved up just fine, drove fine, the synchrometer was just under 6 on all of the velocity stacks, etc. Today it is starting to run rough again. When I was driving into work it quit idling on its own. This is how it started the other day. First it stopped idling then it started running ragged. What in the heck is going on with my car? I would say it was dirt, but I have taken the carbs completely apart and cleaned the hell out of everything. Any opening the carbs have, I have blasted with cleaner and/or air and even cleaned out the throats and butterflies. When I am done, they look brand new. When I put them back on and get them dialed in, everything runs like a dream. What happens from the time I take a few spins down the interstate, park it for the evening, and leave for work the next day? If there is dirt settling somewhere causing a blockage, I can't figure out where it could be. Please help. Any ideas would be much appreciated. Thanks.  

Jeff
72 Super Beetle
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Ryan
Sorry for the delay, been out of town all weekend.  What is your idle speed?  You say just under 6 on the snail gauge, but that's usually pretty high idle.  Most people are never over 5 and idle under 1k.
What's your fuel filter look like?  Also, how clean is it inside the air filter assemblies?  Are the sealing up real well or are they letting dirt in.  Also, have you checked for intake leaks???  I don't want to alarm you but I had a rough running issue a few years ago and could not track it down for the life of me other than I found an intake leak that I could NOT fix.  Turns out it wasn't a leaking gasket, throttle shaft, or anything I was expecting, it was a crack in the head into the intake port...  Check for leaks when it's running poorly.  --Ryan
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staticattic

I didn't drive it all weekend. It rained all weekend, plus my wife really hates riding in it. She says she always smells like gas after riding in my car. I have no idea what she's talking about, she is the only one that can smell it. Anyway, today it started up, idled, and ran fine. As far as idle speed, I don't have a tach. Where it is now, when it is idling with the floats just under 6 on the snail, the idle speed sounds too slow to me. When she is idling, the alternator light will just barely start to flicker. With all of the rasslin' I did with her last week, since she is running good right now, I am really nervous to touch anything. When all of this first started, I sprayed carb cleaner around everything and there was no noticeable change in the engine speed. Maybe I should do it again just for grins and giggles. Other than the carb cleaner method, I don't know of another way to check for leaks.   

Jeff
72 Super Beetle
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Ryan
Carb cleaner is how I do it.
Get a tach...  If you actually are idling too high, then it's possible you have the lowest progression port exposed and it's screwing with your idle mixture screw setting.  --Ryan

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staticattic

Bro, it has got to be a leak somewhere that is causing my problems. It is running like crap again, no idle and only runs well at WOT. It also sounds like a steam engine train, only making the "ch-ch-ch" sound a lot faster. I am thinking this weekend, I need to stop dicking around with the easy stuff and just drop my engine. I do know the gasket between the manifold and the heads is a metal gasket. The Weber book says to use paper instead. I have also heard from some of the local rail buggy guys that I should use two gaskets on each side that are Permatex'd together. Thoughts?  

Jeff
72 Super Beetle
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olspeed

I don't know about the rest of your problem,but you really need to use paper for the intake gaskets on a dual carb setup. I have never had any luck with the metal gaskets on dual carbs,as they always leak sooner or later no mater how many times you re torque them. Go to your local auto parts store and get some thick gasket paper and trace out the gasket using the metal one and then cut it out. As far as the cracked head goes I have had that happen too, if that happens your just done and need to change it. Also I have had one of my tall Weber manifolds crack when I was trying to use the stock metal gaskets. One other thing your wife sounds just like mine must be an echo.

66 Ghia, "Dexter" 76 flat window Beetle
It's not a Car it's a VolksWagon!
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Ryan
NO METAL GASKETS!!!  I use the Bugpack gaskets for ported heads and then cut them to fit.  Don't use any sealer on them, instead smear a light coat of moly based grease.  It helps the seal and makes removal much easier later on.  Only one gasket, no need to double up.  The extra thickness just means more to compress and you'll end up having to re-tighten them over time.  --Ryan
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staticattic
Yesterday, the "ch-ch-ch" sound got really bad. I didn't think I was going to make it home. I had to hold the gas to near wide open just to keep the engine alive. Sitting in stop and go traffic with a car that won't idle is frustrating. Anyway, I took today off from work and set in to it. I removed the fan shroud, both carbs, and both manifolds. Interestingly, both manifolds were wobbly after only loosening the front nut. I replaced the metal gaskets with paper and smeared them with a little Permatex. Probably never be able to get them off. While everything was apart, I also put in a new set of plugs. I thoroughly cleaned everything to what I think would meet Ryan's standards. The virgin Mary would not have been ashamed to eat off them. Once I put everything back together, just for grins and giggles, I removed my rockers and made sure my heads had not worked loose. By that time, it started pouring down rain, so I just threw the rocker arms back on and went inside. Two hours later , when I went outside to try to start it, it would only barely start and only at full throttle. Then I remembered I had not rechecked the valves. They were all tight and on three of them on the driver's side, the ball thing on the top of the rocker arm had rolled around to a round side, not the flat side. Fixed that, adjusted the valves to .006 and wouldn't you know it, it fired right up and was actually idling a little fast. I calmed it down and played with it until the ball in the snail gauge was at 5.5 in all of the velocity stacks. I don't have a tach, so I don't know my current idle speed, but it sounds too slow to me. Almost like it is about to cut off and the alternator light just barely flickers. Either way, it idles smooth and does not hunt or pop. The test drive was amazing. First, the "ch-ch-ch" is gone. Second, it feels like I have a bigger gas pedal. It feels weird as it has much better throttle response than it has had in a very long time. I am not getting too excited as it has always run better immediately after working with the carbs. If it still runs good when I get home from work tomorrow, then this job will be closed. Thanks for all of the help and comments. Hopefully, today's actions will have fixed my problems. 
Jeff
72 Super Beetle
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Ryan
Hope it works out for you.  You'll want to check the manifold nuts after about a week of driving since the gaskets usually compress just a hair.  Also, keep an eye on those tight valves for the next few valve adjustments.  If they were tight from overheating (intake leaks do that), then they stretched.  If they keep getting tight (over the next 3-4 checks), park it and replace the valves cause they are stretching and will eventually break in a VERY catastrophic manner.  --Ryan
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