What causes a Mercedes Benz fuel pump to fail?

Typically problems related to the fuel pump and fuel pressure include: Under normal operation conditions, the fuel pump provides a constant flow of fuel. A failing fuel pump typically delivers too little fuel from the gas tank or in certain cases too much. Mercedes-Benz cars use an electrical fuel pump to pump the fuel to the fuel injectors.

What should I do if my Mercedes fuel pressure is zero?

If your Mercedes doesn’t start, check the fuel pressure. If you are getting zero reading, you either have an electrical problem or a bad fuel pump. If the check engine light is on, consider yourself “lucky” as it can make your diagnosis easier. Note that not all faults will trigger the check engine light.

What should I do if my Mercedes Benz won’t start?

Start the car and you should be able to get around 60 psi. When the engine is running and when you turn off the engine the pressure should stay steady. Always perform this test on a cold engine. Next, make sure that the fuel injector connections are secure and not loose. Check the fuel pump and the fuel pump relay.

What should I do if my fuel pump is not working?

The first thing that you should do is check the fuel pump fuse. If the fuse is good, you will need to test the fuel pressure. If you performed a fuel pressure test and find out that the fuel pump is not generating fuel pressure, don’t rush into the conclusion that the fuel pump is bad. Perform the following test before you replace the fuel pump.

What to do if your fuel pump is not working?

Check out your vehicle’s service manual to find out where to check and the proper procedure for checking it. Test for source voltage, to determine whether or not the good charge that’s leaving the fuse is getting to the pump. If no power is making it to the fuel pump, then check the fuel pump relay circuit.

What’s the fuel pressure on a Mercedes Benz?

A great and affordable gauge that we have used in the past is this Actron Fuel Pressure Gauge which works on Mercedes-Benz cars. Turn the engine off and connect this gauge to the Schrader valve test port shown in the picture below. Start the car and you should be able to get around 60 psi.

When to replace fuel injectors in a car?

This should give the engine enough fuel to run long enough to see if the injectors are working correctly. If they are not, have them all replaced at once instead of just the bad ones as this is a beneficial maintenance practice. Once the problem has been properly diagnosed, your engine should be running again. Was this answer helpful?

What should the pressure be on an electric fuel pump?

Electric fuel pumps on electronically controlled fuel injection systems need to produce enough “high” pressure to allow the injectors to produce a sufficient spray of atomized fuel into the intake path (or into the combustion chamber in a direct-injection system). Fuel pressure is typically in the 35 to 45 psi range.

How much does it cost to replace a Mercedes fuel pump?

Don’t be surprised if your Mercedes goes into limp mode for fuel related problems. Use Star Diagnostic scanner to perform a complete system scan. To replace the fuel pump on a Mercedes-Benz, it costs between $450 and $800 depending on the MB model. You will pay about $300-$450 for parts (fuel pump) at the dealer.

Where is the fuel pump in a Mercedes C280?

The fuel pump in the Mercedes C280 is in the rear of the car on the passenger side near the fuel tank. The pump is directly next to the fuel filter under the chassis of the car behind the passenger side, rear wheel well.

How to change fuel filter on Mercedes W211?

This is dangerous!! Only a licensed mechanic should perform this procedure. In this video I show what I did to change my fuel filter on a 2006 Mercedes E320 CDI ( W211 ) diesel. The tools I used were a torx driver set, needle nose pliers, a philips screw driver and plenty of rags. There was fuel that spilled out of the lines. Loading…

Where is the fuel filter on a C350?

The filter is located under the access cover.Begin removing it by disconnecting the two electrical connections (red arrows).Then give a good cleaning around the retaining ring and lid.

How do you remove a fuel pump from a car?

You can open a black plastic door in the wheel well using an 8-mm socket wrench which allows access to the pump for removal. The function of the fuel pump is to deliver the right amount of fuel from the gas tank through the injectors and into the engine.

How can I check the pressure on my fuel pump?

Attach the fuel pressure gauge at the fuel rail test port. Cycle the key on and off a few times and watch the pressure should go up to specifications and not drop for a long time or more than ten minutes before any drop of more than 1 or 2 psi is seen.

How to troubleshoot a Mercedes Benz fuel pump problem?

Troubleshooting a bad fuel pump problem on a Mercedes-Benz is easy. This is a job where you need to be extremely careful because you will work near fuel and there is always the risk of fire. It is recommended that you empty the tank or have the fuel tank near empty when you replace the fuel pump.

Which is a symptom of a fuel pump problem?

Another symptom of a problem with the fuel pump is engine performance issues. As the fuel pump is what supplies the vehicle with the fuel required for combustion to occur, any issues with it can affect the engine’s fuel supply and cause issues.

Can a weak fuel pump cause a car to not start?

A weak fuel pump may still pump fuel, but the vehicle may experience difficulty starting from the lack of pressure. A weakened fuel pump can cause the vehicle to take more cranks to start than normal, and in more serious cases may even cause the vehicle to require multiple turns of the key before it will start.

What causes a Mercedes Benz fuel pump to fail?