I experienced the same thing last weekend driving my grandad's 1990 200E W124.
He swapped out the spark plugs and cables, popped some injector cleaner and the problem was gone. It was all done at the same time so we don't know which was the cure...
Sounds like the same problem coz halfway during acceleration (50% throttle), the car would start hesitating/jerking. In this car, there was no "pop" but the symptoms sound the same as your problem.
Hope this helps for what it's worth. Good luck!!!