captainwes

My 2006 R350 has just turned 80000 miles and I have developed a start problem. It would crank but not fire, so my dealer said the fuel pump needed replacing. The car started at the dealer's, but when I got home and tried to start it, it would crank but not run. The CPS was O'K but another dealer replaced the ignition control relay and seemed to cure the problem. After a few months, I had the same no start situation, so I replaced the relay and all seemed well for a few starts and then no more starts. I found by removing the relay for a few minutes and then replacing it would make things work but after 5 or 6 starts, ,my problem would return.
Any suggestions before I go back to the dealer for more expensive and ineffectual work?

xclream

Not sure if you are still having this issue.

My R350 (2008) which only has about 44,000 miles, had the exact same symptoms as yours. Last week, I started noticing, when I start the engine, it would take 8 or more cranks for the car to fire up. I didn't worry too much initially, just thought maybe I had some moisture in the gas tank. Then on Friday, after I dropped my son off school, I got back to the parking lot, it just kept on cranking but not fire up. Had it towed to my mechanic and he replaced the fuel pump for about US$600 (parts & labor) and it fixed the issue. The car would even feel peppier after you get a brand new fuel pump.

Thought I share it with you.

PS - What is going on with MB quality, 44K and fuel pump is gone. Never heard of this issue with Japanese cars.