Mercedes B Klasse fuel injection issue

Sounds familiar I had a similar issue with my old Volvo Reduced power and stalling are classic signs Fuel injection systems are sensitive Have you checked the basics like the fuel filter Also inspect the wiring harness and connectors related to the injectors themselves A loose or corroded connection can definitely cause those symptoms Higher fuel consumption usually means the system is dumping too much fuel so you need to get that checked Smoke indicates unburnt fuel Do you have the tools to check the voltage at the injectors

I have checked the fuel filter and it seems to be in decent condition I haven't had a chance to thoroughly inspect the wiring harness and connectors yet but that's next on my list When you mention checking the voltage at the injectors could you elaborate a bit on how to do that properly and what readings I should be looking for I have a multimeter but I'm not an expert in electrical diagnostics I'm worried about causing further damage Your help is much appreciated

Alright so you have a multimeter Good First you'll need the wiring diagram for your Mercedes find the injector circuit Disconnect the injector connector Set your multimeter to measure DC voltage With the ignition ON but engine OFF probe the connector pins One should have battery voltage around 12V The other is the control signal from the ECU Engine Control Unit When the engine is running that signal will pulse as the ECU controls the injector A steady reading or no reading indicates a problem Honestly if you're not comfortable with electrical diagnostics I'd advise taking it to a workshop A faulty reading can also mean a failing ECU so be careful and don't replace parts without confirming they are faulty

Thank you so much for the detailed explanation and the cautionary advice I followed your suggestion and took the car to a trusted mechanic Turns out you were spot on about the wiring harness A connector leading to one of the injectors was indeed corroded and loose causing intermittent contact and the issues I described They cleaned and secured the connection and the car is now running smoothly again The total repair cost was around 95€ as initially estimated I'm incredibly grateful for your help in pointing me in the right direction and preventing me from potentially causing further damage