I have an 83 w123 300DT and a strange acceleration problem that recently developed. When accelerating at 3/4 throttle there is an intermittent surge or pulsation that feels like the transmission is thinking about downshifting. The pulsation cycles are in harmony with a faint clicking, like that of a relay. I pulled the HVAC controls, shifter surround and glove box trying to find the noise, or associated relay, but it seems as though it may be coming from under the shifter. I tried disconnecting the kickdown solenoid at the pedal, but the pulsation and faint clicking continued. Thanks for your thoughts.