FAQ 01
Question: I'm running a Weber DFEV and 009. My weber carb seems to be jetted wrong. How do I adjust the DFEV carb? Should I keep my 009 distributor? If I go back to a 205 distributor, where do I connect the vacuum advance tube? Answer: Before anything, you'll need to make sure your choke is adjusted. I'm guessing that you have the electric choke (The E in DFEV is for Electric.) Adjust the choke with the engine off, and cold. There are 3 small screws that hold the choke adjustment. It is a round thing, facing the fan shroud. It's kind of hard to get to. I usually use a combination of small sockets and distributor wrenches. Mark the housing the carb body with a Sharpie before you start adjusting, so you know where it used to be. Just loosen the three screws. I think you turn the electric choke housing the opposite direction that you want the choke plate to move. You'll have to open the the throttle for the choke plate to move freely. When the engine is warm, the choke should be fully open. By the way, all those carb adjustments need to be done on a warm engine with the choke fully open. The choke has an electric heating element in it, therefore you need to have a wire from the + of the coil to the connector on the choke. Initial setup of a DFEV is tricky. You must do the jet and idle speed adjustments with the engine warmed up and the choke fully open. Follow these basics: Back off the idle speed screw (on the linkage) until the throttle closes. Then turn the screw until it just touches. From there turn the screw exactly ONE turn. Start the engine, and allow it to warm up. Make sure the choke is all the way open. Now set the idle mixture for max rpm (presuming that the distributor and timing are exactly right). After all this, go back and use the idle speed screw (on the linkage) to set the idle speed to 900 or so. This is the correct way to set the mixture and usually cures most problems. People tell me that the 009 is a good distributor. Before anything drastic, make sure your car is prefectly tuned, and that the carb is perfectly set. I'd guess that your idle mixture is off, and maybe you have a vacuum leak. As of April 2001, my thinking is that flat spots in the accelleration are due to a cold intake manifold, and perhaps too much ignition advance. The optimum temperature for the intake manifold it probably well over 100 degrees F. I have both my heat riser and the stock air cleaner with warm air inlet from down by the pushrod tubes. The warm air connection to the air clean required building an adaptor for the stock air cleaner (which I've since found mail order). Sadly, this whole setup may not fit under the engine cover of a stock Bug. All this extra manifold heat makes a huge difference in cold wet weather. Before installing the heat my Bug wouldn't idle in 40 degee F rainy weather. Now it occasionally has some problems, but it warms up quicker, and nearly always has a nice, smooth idle and accelleration regardless of weather. I'm actually looking for more intake manifold heat. Incidently, I removed my engine thermostat and cooling flaps. That was a big mistake. If you have too much initial ignition advance, then you'll probably set the idle speed screw too low. This makes the transition from idle to just off idle not work correctly. I had my Weber setup wrong, in large part due to too much initial ignition advance. Right now I'm running about 5 degrees before top dead center (BTDC) with a 205 single vacuum advance distributor. Here is a little story: I had a Weber DFAV on my old Datsun 510. It always ran perfect! The 510 engine is an inline water cooled 1600 cc, overhead cam. The BIG difference is that the 510's intake manifold is heated with engine cooling water, and the manifold is only about 4 inches long. Between the engine coolant and being bolted directly to the cylinder head, the 510 manifold is probably 140 degrees F. I know it was too hot to touch. My 510 had something like a 170 degree thermostat, so the intake manifold was being heated by water at near 200 degrees F. The 510 had amazing power, and no flat spots. I also have a Weber DGAV on my BMW 2002. Runs like a charm. The intake is also heated, and is short and bolted directly to the head. Neither of these cars had heated intake air. If you have your carb apart, check the float level. This was not a problem with my carb, but it's worth checking. The fuel level in the float bowl effects the fuel level on the emulsion tube. The emulsion tube works with the air bypass jet and seems to effect rate of fuel vaporization. This means that float level is pretty critical. Jetting is difficult. I've read one of the weber manuals, "All About VW Performance Engines" from Hot VWs magazine. It's a complex process, and perhaps not necessary. Info about the books (and mail order places) is online at: http://laudeman.com/bug_links.html The boots at the ends of the center manifold section often leak. Best to replace them with new urethane parts. Vacuum leaks cause bad running problems. Keep your 009. If you wanted to go back to the 205, you want the venturi vacuum on the middle of the side of the carb. This vacuum is low at idle and goes up as engine speed increases. You can verify this with an inexpensive vacuum gauge. On the other hand, manifold vacuum is high at idle and goes down at speed increases.
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