I have an 82 240 which recently stalled on the freeway going about 60mph. Earlier in the day, I had changed the oil and adjusted the fan belt. The car had been running without problems for a long time, except for the fact that the car would be difficult to start unless it had been driven within 2 hours. Previously(2 years ago), it had stalled several times. I fixed a vacuum check valve to the heater vacuum chamber and that seemed to fix the problem (the car ran much more smoothly). But maybe it didn't? I am wondering if this recent stall could be related to the wiring harness under the engine, which we may have bumped when adjusting the fan belt.