iI also have a fuel suction issue that stops me at about 1/4 tank. I have been opening the tank cap relieving the suction and filling up before i have problems
Could be a plugged fuel tank vent or in tank fuel strainer.
how are your fuel filters?

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1981 240D 143k 4 spd manual -SOLD

2004 VW Jetta TDI 5 speed 300k -still driven daily