I have had some customers experience a lean condition even though all of the correct parts were used and worked properly. This has been more of a problem with dual carb, higher HP engines than with a stock single carb. With one instance, everything was tried relating to the engine and fuel pump, all to no avail. At about the same time, we had the gas tank out of our race car and were installing a larger size gas line fitting. It dawned on me that this is an area which is of extreme importance and that many people are unaware the gas tank has a filter screen and should be changed periodically. The screen part number is, VW 111-209-147A, gasket, VW 111-209-139 all for just a few dollars. Because it is out of sight, it is not the first place you would look so I called the customer and asked him to pull the tank out and check his screen. As it turned out, it was plugged badly and a replacement was in order. This solved the lean condition that was caused by fuel starvation from the tank to the pump when the engine was being used under higher performance applications. I have had many more such cases of this since that time and I can assure you that is now the first area I have the customer look. |
I suggest that on all cars, that have such a screen (some late 1970's do not), it should be checked periodically and/or replaced. Especially with a high performance engine that could require more fuel than the stock carb. Even a stock vehicle may benefit from a look at the screen from time to time. The parts are cheap and not too hard to install. It could just save you from leaning your engine out and causing premature damage. |
The vent tube hose and charcoal vent system must also be is in good condition so air can come into the tank properly. If you need to go to a larger outlet I used the one from a fuel injected Type III and the Type III steel line from front to back. When I went to the AN-8 I had the tank cleaned at a radiator shop and welded the AN-8 fitting into the bottom of the tank. | |