Mercedes A Klasse diesel engine issue

The symptoms you describe poor starting and increased fuel consumption could indeed point to a defective throttle valve In my experience similar issues arose with my previous vehicle a Vauxhall Astra The engine throttle became erratic and the air intake was clearly affected It may be worth checking the accelerator pedal module as you suggested A faulty signal from this module can disrupt the engine idle and compromise fuel efficiency Have you considered inspecting the wiring and connections associated with the throttle valve and the accelerator pedal module Also a diagnostic check might help pinpoint the problem

Thanks for the reply Wiring and connections are fine I checked that already By diagnostic check do you mean an OBD reader And what exactly should I be looking for in the data Is there a specific sensor that usually fails or a certain error code

Precisely an OBD reader When you perform a diagnostic check focus on error codes related to the throttle position sensor mass air flow sensor and the accelerator pedal position sensor These components directly influence the air intake and overall engine throttle If any of these sensors are providing inconsistent or out-of-range readings it could explain the poor engine idle and decreased fuel efficiency you are experiencing Considering the potential complexity and the impact on fuel efficiency it might be prudent to consult a qualified technician for a thorough inspection and repair It may be beneficial given the risk of improper adjustments to the engine

Thanks for the confirmation that helps a lot Took it to a mechanic and it turned out to be a defective accelerator pedal module as suspected Total cost was 205€ including parts and labor Runs much smoother now and the fuel consumption seems normal again