Themurphyco

I parked my clk430 last fall. It had bad gas and ran rough. I just got it back after 10 years from my ex wife who had it parked for 8 years. After it wouldn’t start, I checked the fuel rail. No pressure. Since it never had a fuel filter or pump put in for at least 10 years, I put a new Bosch pump in and a Mahle filter. Still no pressure. It will run if I spray carb cleaner through the MAF. It also won’t take any gas. I tried to fill it and it just gurgles and backs up out the fuel neck. What’s my next step?

CaliBenzDriver

your new tank pump is unable to build up rail pressure...

> Have you checked power supply is good and t's drawing power between 6 and 10Amps ? Could be a bad R-SAM fuse or relay...

> Is the spring & ball pressure regulator stuck open or shut and blew up a 50PSI hose with uncontrolled pressure?

streborx

Does this car's fuel system have a fuel boost pump submerged in the fuel tank?

Rockster

That's a toughie. In one case I came across a car (in the service department of a dealer I used) that had sat unused for several years. It had sat outside in the Livermore CA area exposed to considerable swings in temperature.

Car flat bedded in because the engine would not start. Tech told me the fuel lines had no liquid fuel in them just some powdery residue. The fuel tank had to be removed and cleaned. The in tank fuel pump and fuel level hardware had to be replaced along with the fuel lines, filter, and fuel rails and injectors.

But I have come upon other 2nd hand cases where the car has sat for some years -- in some cases more than just several -- and fired right up.

Given the symptoms I'd say in the case of your car it is probably going to require a pretty full replacement of the fuel system hardware with a thorough cleaning of the tank. The fuel vapor recovery system will likely need some attention too. (The inability to add fuel a clue this is necessary.)

streborx

This is likely the required remedy. All the fuel additives present in gasoline (and diesel fuel) today leave behind nasty residue. I have several small engine appliances on which I've installed fuel valves. Each year before storing them, I shut off the valve, run them dry, and drain out the residual fuel. When I've not done this, I end up having to yank the carburetor and do a complete disassembly and cleaning to get it functional.