'86 300E EHA system problem?

EHA system problem?

My ‘86 300E with 150K has a hesitation/miss when taking off from a stop (when warmed up) until it gets above about 1800 rpm. Otherwise it runs, idles and starts good. After searching other posts, I tried disconnecting the EHA which made the hesitiation/miss go away. Does this mean the EHA is just doing its job and I should check other related components before replacing it. Although I don’t see it leaking, it is a bit wet with fuel. I’ve already checked or replaced all ignition components plus replaced the fuel injectors. What about the O2 sensor?