Just something to share, may save someone a headache. Over the last couple of months my 250sl was running okay, a little sluggish when pressing down the accelerator, smell of gas odor when stopped at a light, and lingering gas odor when sitting in the garage after a drive, no gas leaks, and the odor in the garage would eventually disappear after a few days. Since the car was running ok, and I had other more pressing issues to deal with, I figured it was a fuel mixture, timing, wrd issue of some type to eventually sort out at some point in the future. Last 2 fuel fill ups, I heard the notorious "swooshing" sound while removing the gas cap. Having been educated on this forum about the "swooshing" sound I took the car to the shop and we blew out the gas tank vent lines with air, cleaned out the funnel vent device, which did have debris in the lines. Took all of 15 minutes.
On the way home unexpectedly I noticed a huge improvement in performance, I would say at least 35-40% better no sluggish feel when pressing down on the accelerator, no gas oder at a stop light, no gas ordor in the garage and no swooshing sound. Amazing what a difference such a small fix did.
If your having performance issues while accelerating, instead of making yourself crazy messing with fuel mixtures, timing, warm running device,,, I would take a look at the gas tank vent lines, may save you headache.
