1982 240 looses power on freeway

If the fuel filter hasn't been changed in a while, that would be a great place to start. My experience with plugged fuel filters is that they often recover a bit when they sit for a while (I assume the debris falls to the bottom when pressure is relieved) and then plug up again some time after the car gets moving. The restriction is most important when the engine is trying to gulp a lot of fuel.

Mike

I've had similar problems with two different cars in the past... the first time, it was debris in the gas tank that would clog the intake filter, slowing and eventually stopping the car... after a while, the debris would float free and I could drive the car normally again, until it re-collected and blocked the flow of fuel. The fix was to drain and clean the tank, and install a new sock filter on the intake...

The second car had a problem with the cat converter... the matrix inside had broken apart, and rolled around until it was just a round ball, like a billiard ball. While driving, it would sometimes roll into the outflow opening, causing severe restriction and slowing... again, when I would pull over and stop the engine, it would apparently roll free and I could drive away normally... The fix was to replace the cat converter.

I own an 83 240. Once apon a time it would drive perfectly in the city, but hesitate on highway driving/heavy use. It turned out there was debris in the fuel tank that clogged the in tank fuel pump. For a few weeks it would drive fine after a 5 minute rest as you describe, but eventually whatever clogged the pump caused it to fail completely. The car suffered vapourisation repeatedly, and lost a lot of power. May i suggest you drain the fuel tank as a precaution, and while you are doing that check the in tank pump. If you start the car and put your ear to the fuel cap you should hear a faint buzz. Hope its nothing too serious

Josh