All weekend – I tinkered, I read, tinkered and adjusted some more, read some more… This is what I did all weekend. So far, I have learned a crazy amount of information about how VW carburetors work, and I have adjusted and tinkered with every available aspect of the devilish Bocar 34Pict-3 that sits atop my 1974 Super Beetle bastard of an engine. Finally, Sunday evening, the bus starts right up, idles smoothly, warms up, keeps on idling, shifts into gear cleanly, and most importantly – doesn’t die every time I come to a stop – Success!
But, like everything with this crazy bus, there is more to the story. After all my efforts this weekend, I have determined that the carb has a somewhat large vacuum leak coming from the heat riser gaskets, the intake manifold gaskets, and/or the throttle plate bushings – yes I learned all of these fun and interesting terms this weekend – I’m just cool like that! To compensate for the additional air flowing into the system from these leaks, I have backed out the idle adjust screw on the right side of the carb, thus adding more fuel to keep the fuel/air mix balanced. It’s a temporary fix at best, but it does keep the engine running smoothly when I let of the gas or come to a stop. I am thinking that I will order a carb rebuild kit, or potentially even a full replacement unit eventually; but I’ll drive it as is in the mean time.
In addition to my carb fun, I also replaced the fuel filter – the old filter has usually been empty before starting up the bus – when I loosened the clamps and pulled the hose off – oops! Of course the thing is actually full this time, and I just dumped a decent amount of gas all over the garage floor. I rushed to grab the oil pan just in time to catch the last drop as it rolled off the side of the engine. Great, just great! I cleaned it up as best I could; it didn’t leave a stain, and actually looks like it cleaned the garage floor a little – I’ll have to remember that next time I go on a cleaning spree – just kidding!
Finally, my copy of the massive, venerable Bentley Workshop Manual for the bus came in. This thing was expensive, and is the book that everyone refers to on the forums when they actually solve a problem. It helped me learn about the carb, and has detailed instructions/ photos/ diagrams for every minute aspect of the bus – looks like I just got some more light reading!
Reddit sent me here. This is very cool, I appreciate you doing this.
Following along now. If I end up with one of these projects, and the wife wants to know where I got such an idea, I am blaming you.