Hello folks,

As you all know the common fuel smell issue of our W205 C300 M274 Engine, I can see a little wet spot on the high pressure pump cover so decided to change out the hose clamp.

After removing the high pressure fuel pump cover, disconnect the plug, unplug the hose from the pump, put new clamp in and reconnect everything - The engine only cranks but no start! I made sure everything is plugged and tight, nothing is leaking, primed the fuel pump 10+ cycles by turning ignition on and off, still engine no start.

Then I removed the hose and turn ignition on just to see if the fuel pump is working the fuel up and yes it does work as I get a lot fuel pumping out from the hose. Reconnect everything again but still engine no start only cranks.

It’s very odd as the car was working perfectly fine, all I have done is unplug the wire of high pressure fuel pump, and fuel hose. Scan the computer, there is no codes pointing to any issue.

Have you guys ever encountered this issue before? And what was the solution?

Thank you for any advice!

 

Hello, you need to be very careful when changing the high pressure part. Why did you open the high pressure? You may have damaged the high pressure also you only need to let the car set in ACC 4 times to prime the system but do no start the engine. If you did start the engine and priming the engine at the same time, you will damage the high pressure part.

 

Sorry to hear this OP, did you ever managed to fix it?