I had some plastic fuel lines and o-ring seals replaced several months ago after experiencing significant fuel leaking from the pump. Ever since I got it back, I have noticed what I would call a "hesitation" or hiccup in acceleration on changes to accelerator position.

It's much more pronounced at higher engine rpm's- for instance, if I am driving along the highway at steady 65 or so, if I gently release accelerator pressure and slow down a little, if I then depress the accelerator pedal to speed back up, I will notice a momentary stumble or hiccup before the car actually produces power. This is also very pronounced if I keep the transmission in 2nd gear and run the car up to a steady 3,000-3,500 or so rpm, reduce the power momentarily, then increase power.

It is definitely NOT turbo boost/lag related, and feels much more like a fuel delivery issue. I have also noticed a drop of a couple MPG as well as possibly a little more exhaust smoke under heavy acceleration- (not at idle) *NOTE that ALL of this has only been a problem since AFTER the dealer did this work on the pump and fuel lines!! I also think the engine sounds alot more "diesel like" than it ever has...much more nailing/clatter sound.

On the invoice, it also said they set the pump timing (which I NEVER told them to touch!!)

Could this be timing related, or perhaps did they introduce some contamination into the fuel system with the pump lines off, and I now have something partially clogging an injector or two?

I have not tried to use the diesel fuel purge as there doesn't seem to be a "cigar hose" to introduce it into the fuel system (maybe hidden under the intake manifold??) (much easier in the old 240D!!)

ANY help would be most appreciated!!

J.G.