I have a 97 mercedes benz c 280 and I've been experiencing issues when refueling. Whenever I reach aprox 6 gallons (1/2 tank) the pump will trigger the automatic cut off. After that point it's an annoying process of what someone would typically experience when "topping off" their tank. Holding the trigger only to have the automatic cut off stop the pumping. On occasion I've found gas on my tire. Inspecting underneath the car I have not found where it's coming from exactly but I'm assuming it is a relief vent for the gas tank. Has any one ever experienced this? Was there a solution?

The sending unit is apart of the fuel pump and it definitely sounds like the sending unit is bad.

Diagnosing Mercedes Benz Misfire DTCs Auto Service World
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you didn't say if you replaced/cleaned distributor cap might be worth a look and also spraying inside the cap with wd40

I believe it is integrated in the K40 relay module in the front right engine compartment next to the ME control unit. I also believe the 97 W210 relay was moved outside of it. That fuel pump should be outside of the tank so it will be easy to test for power and ground at the pump if you are having a fuel related issue. I have replaced many more fuel pumps on these vehicles than relays. I usually replace the relay as a precautionary measure, but not because it failed. I hope this helps you.

did you plug it into laptop to check if sensors is right?

you need to check the breather hose from the fuel filler going to the tank. you may need to replace or fix them to avoid air pocket while filling gas.

There are many reasons why fuel pumps have no power, most (in tank) fuel pumps fail due to low fuel inside of tank.

These fuel pumps turn at an alarming rate which in turn causes an alarming amount of heat. This heat is then dissipated by the fuel inside of the tank itself.If the driver/operator allows to run the fuel very low and continue to do so, this will over time allow for the fuel pump to overheat due to the ONLY source used to cool the fuel pump is the fuel inside of the fuel tank itself. Electrically, view the operator's manual or similar source to locate fuel pump fuse and/or relay of which will open the electrical path when the fuel pump overheats.
This should be a pretty good starting point to locate/isolate electrical issue you may be experiencing.

Good Hunting to you & hope this gets you back on the road soon!
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Fuel pumps are usually located in the gas tank...Hope this helps.

hey

2.3 L displacement but with the same output, although with torque increased to 220 N·m (162 ft·lbf). . The top of the range was the C 280, with a four-valve-per-cylinder straight-6 engine, capable of reaching 193 PS (190 hp/142 kW).

Damien