Benz_Pro

The vehicle runs leans during acceleration. I have replaced both front o2 sensors, when I reset adaptation values watch lambda values and accelerate during test drive vehicle is lean. My idle adaptations are near perfect my part load adaptation is 1.32 left bank spec is 0.7-1.3 my right bank part load adaptation is 1.27 still within spec but close to going out and setting code also. I have also replaced the map sensor to make sure calculated air should be correct. No codes for fuel and run over 170bar highside fuel pressure while accelerated. I now believe some fuel injectors must be slightly clogged and not supplying enough volume under higher load. Is there anything I can do to test Injector. I am aware or injector balancing tests on other di vehicle but mercedes does not have this. I have factory scan tool xentry and an autel im608.

VII

Need fuel pressure under load, not solely accelerated.

Unlikely all fuel injectors have a problem but can always remove and send for clean/test.

VII

Most likely a pump issue under load on the low or high side.

Benz_Pro

I am testing high side fuel pressure while driving underload. The fuel pressure never drops. Maybe scan tool can't see it drop fast enough. Does anyone know how the two high pressure fuel pumps work. Is one for each bank or do they common rail/connect together?

Katie22

Ok so this might not apply for you but I did look up a fuel injector and it appears to be electrical solenoid. Last weekend I replaced ONE fuel injector on my father in laws Pacifica Van. The way to identify the bad injector was to measure resistance with an olm meter on each injector. The bad one was WAY different measurement than the rest. All were around 16 olms and the bad one was 35 olms. Van ran great but was pulling a lean code on the front cylinder bank.