I have a 1985 XJ6 which was giving me trouble with the engine dying - at first on an intermittant basis, and now on a consistant basis. The engine fires up immediately and then dies after about 5-6 seconds. With the help of a friend who is fairly knowledgeable about cars, we finally diagnosed the problem as the air flow meter. The flapper valve inside the body under the black plastic cover opens up upon starting but then closes after a few seconds, and the engine dies. If I manually hold that flapper valve open, the engine continues to run. I have been told that rather than buying aother air flow meter, that the pre-tensioning can be adjusted or tweeked. If anyone knows how this is done, I'd very much appreciate if you could explain to me how to do this.

Thank you
Ray