What about the distributor? In my '88 Volvo (PoS) I had choking problems while cruising, it felt like the clutch slipping. I also had the occasional problem where it wouldn't accelerate past a certain RPM. Turns out the distributor wiper was so bad that the electricity was arcing across the wiper since there was no physical connection.
QUIST: Why do you ask about the washing? Like, if the answer were yes, then what would you propose as the cause of the problem?
b