83-240D,

How much fuel does the tank accept when you fill it back up? It is possible your tank sender for fuel level and the reserve light is malfunctioning and you are just out of fuel. This has happened to each of my cars as they aged. You get to depend more on the mileage and less on the sender unless you fix it. I never bothered, and just used the trip odometer when I filled up.

If you have a hole drilled in the cap you don't have a vent problem. Going around corners may cause a bit of fuel to dribble out and make the side of the car wet with fuel. This will cause dirt to stick and make the car look messy. But with a hole in it the need for the vent system, or the need for a functiong vent system is superfluous.

If you have fuel and you are not getting it when the tank gets down to some level, you have some foreign material in there. I once had a VW bus and it acted similarly. I used to take the carb of every night and clean it, then put it on in the morning. One day while putting the unit back together, I noticed something inside the fuel line. Turned out to be an entire 8-track tape! I pulled it out, slowly, and then, no more problem. Once the fuel level is low enough, the suction of the pump will draw the foreign object over the tank port feeding the pump and soon there is no flow.

The smoking you see is likely by-pass gasses and is a sign the rubber connectors are shot. The whole point of the cannister is to separate oil droplets from non-condensing gasses in the blow by, send the gasses back to be burned again, and collect and drain the oil droplets and condensibles to the sump. Leaking connections also makes a mess and they are relatively cheap, so get some new ones (there are five rubber connections as I recall, one at each end of the tube from the valve cover, one on the line going to the sump where condensed oil vapor drains, and one on each end of the tube going to the intake). I change them all when I do it.

Good luck and I hope this helps. Jim

__________________
Own:
1986 Euro 190E 2.3-16 (291,000 miles),
1998 E300D TurboDiesel, 231,000 miles -purchased with 45,000,
1988 300E 5-speed 252,000 miles,
1983 240D 4-speed, purchased w/136,000, now with 222,000 miles.
2009 ML320CDI Bluetec, 89,000 miles

Owned:
1971 220D (250,000 miles plus, sold to father-in-law),
1975 240D (245,000 miles - died of body rot),
1991 350SD (176,560 miles, weakest Benz I have owned),
1999 C230 Sport (45,400 miles),
1982 240D (321,000 miles, put to sleep)