I am new to this forum and am looking for some advice as how I should proceed.
I have a 85 190e that has a strange problem, At any speed above 40 mph, the engine surges slightly as if the fuel pressure is being turned down and up. I have tried adjusting the mixture and it seems to make little difference other that it seems to decrease slightly the surging if I richen the mixture. another thing that I have noticed is that if I am making a right turn, it seems not to surge too much, but if I make a left turn is seems to get very noticable even with a full fuel tank.

I am thinking it may be a bad fuel pump or possibly a binding fuel injection head unit but am not to sure since I am new to this car.
Any advice would be greatly appreciated.

thanks and best regards, Jim