Have a 93 w250 thats also sluggish. Replaced a lot of parts with not much change. I did change the fuel filter and it seems to have really helped. Also if you have a vacuum gauge it will tell you alot about the engine. Should have a minumum of 17 at idle.

 

Well, I replaced the fuel filter last night and drove it around. It feels the same as before. Could it be a gummed up carb? Is there a how-to on removing it for cleaning? There's a million vacuum hoses connected to it!

I noticed that the brakes clamp at times. Could they be dragging?