My 2013 D40 would almost die after taking off from most traffic lights. Had Vac value replaced but it made no difference. A friend put me on to a product called Fuel Doctor from Super Cheap. I put in 500mls called a shock treatment and it immediately made the engine run smoother and not die a little at gear changes. The almost dyeing at traffic lights has almost gone away so I guess it is slowly eating the gummed up fuel control value.