Sudden really bad misfire - I'm running out of ideas now!

[Erik G]

for the carb linkage - did you look at the "look listen do it better" docs here? there are specific measurements for the linkage that will greatly help

[veedweeb]

[vwfye]

Principle is still the same. Tune each carb without crossbar, then balance.
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64 No'back Speedster "Pearl"
1980s Sand Dragster "The Plunger"
LME "Little Giant Killer 3"

[Tram]

There's a small ground strap inside the distributor that grounds the moving top plate that the points ride on to the body of the distributor. If this little bastard is open somewhere it can cause ALL sorts of issues. Move it around, don't just look at it. It can make contact and then break contact as the breaker plate moves under the influence of vacuum.
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Немає виправдання для війни! Я з Україною.

[veedweeb]

[veedweeb]

[Bobnotch]

[veedweeb]

Okay, so this is still ongoing but I'm making progress.

It's taking a while because I don't need to use the car and it's not really a priority to fix it, plus I've got my '63 Bug that needs attention as well.

Anyway, I swapped the manifolds and sorted out the balance pipe. The linkage needed modifying too because the carbs are now almost 2" further apart.

Whilst I was doing it, I discovered a bad fuel leak from the LH carb accelerator pump so I took the carb off to sort that. It definitely wasn't leaking before - I would have noticed because I'm absolutely paranoid about fuel leaks.
When I had the carb apart I took the top off to check it over and found a bit of debris blocking the jet so I cleaned that and checked the others in both carbs.

So it's starting to look like that was the issue all along. The trouble is, I now need to go through the carb setup and balancing procedure all over again. No biggie really but I ran out of time this weekend so it'll have to wait for another day.
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1963 Turbo WBX Bug
2000 Sedan Clasico Mexican Bug
1972 Type 3 Squareback

[veedweeb]

Fixed it!

Just to recap - the misfire gave all the symptoms of a bad condenser so because the rest of the ignition system was unknown as well, I changed everything: Points, coil, rotor and cap, HT leads, condenser and spark plugs. Then I checked the timing and made sure the valve clearances were all OK.

Next up was a suspected vacuum leak and I didn't like the way the balance pipe was set up, plus I found a vacuum leak on the distributor can on the retard side.
It was at this point that I realised it had stock inlet manifolds with the ICTs on top of them which explains why the air filter was crushed against the underside of the boot floor.

A pair of new manifolds solved a few problems - they're shorter for more air filter clearance, they have a simpler arrangement for the balance tube and they don't have the vacuum take off for the distributor retard. The downside is that they also push the carbs farther apart so I had to rethink the throttle linkage. Luckily the plates that mount on the carbs can be fitted in 2 positions so it was just a case of relocating them.

It was at this point that I discovered some crap blocking a jet in the LHS carb so I stripped them both and cleaned them out.

Then I put it all back to together and went through the whole set up and balancing procedure from scratch and it's running better than ever now!

The combination of a completely new ignition system, along with zero vacuum leaks and properly balanced carbs has done the trick. It will now pull away from standstill in 3rd gear with no problems. It couldn't even do it in 1st before!

Thanks for the input, everyone. I got there in the end!
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1963 Turbo WBX Bug
2000 Sedan Clasico Mexican Bug
1972 Type 3 Squareback

[Bobnotch]

Congrats with sticking with it until all of the little fixes came together and fixed it. Good work.
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Bob 65 Notch S with Sunroof
71 Notch ...aka Krunchy; build pics here;
http://www.thesamba.com/vw/forum/viewtopic.php?t=249390 -been busy working
64 T-34 Ghia...aka Wolfie, under construction... http://www.thesamba.com/vw/forum/viewtopic.php?t=412120