I have a 1988 560SL with about 130,000 miles. When I hit the accellerator to pass a car... this thing starts bucking and coughing at about 3200 RPM. On the Highway, it hits at about 70 mph... but on the sideroads... whenever the enging hits about 3200 RMP... watchout! I have to back off... then things are fine.

The car accellerates strongly... very strongly unless I really step on it.

What's the deal?

Thanks for the help!!!