I've had my '04 jetta (PD BEW) for a few days and its been perfect until now. It has started to take a few seconds to crank (3-5 seconds) and now when I drive it, it dies when I press the clutch in )to go into neutral) when I come to a stop at a stop sign or light. I just bought an additive for the fuel that cleans injectors and what not. I also ordered a fuel filter through work, should I drain/clean out the tank when I replace it? Thanks!