One more thing: I don't know if you have owned your car for long or know its history but it seems this type of problem with 126 vehicles comes from sitting for months or years with partially filled fuel tanks which permits water vapor to accumulate and condense in the fuel tank. This leads to rusting of the inside of the tank and varnish/coke deposits. This can cause a multitude of problems and led to a now ventless fuel tank in my 1983 380SE and the problem referenced in post #6 found here. Mark

http://www.peachparts.com/shopforum/showthread.php?t=99935