mercedes 460 with ether only

Sounds like the fuel system's losing its' prime or it might be electronic.

Or- the fuel lines aren't routed properly.

http://www.ddcsn.com/cps/rde/xbcr/ddcsn/ch8_mbe4000.pdf

 

it is air in fuel issue. Mercrdes makes good fuel systems and truck keeps running with some cracks in fuel lines, but wont starting well

 

Hi pichu- I would go with Pablo's advice, fuel is leaking out of the system somewhere after it's turned off. Once air gets into the injectors you'll need ether to get it to start. There's a check valve that keeps fuel from draining out when the motor's off, that's a good place to start looking. (I've never actually seen it but it's in there- or should be). A lot of the fuel lines on an MBE are plastic- they get dry or fatigued and crack. When they do, it's hard to find where it's leaking from because the fuel goes all over the place.

The only other thing that comes to mind is ECM voltage. Your ECM has its' own battery connection-if that's corroded or damaged or that battery's no good and the ECM's not getting enough energy the engine won't start. Once the alternator starts providing energy (starting on ether), it's getting the proper voltage.

And.. let's see- primary fuel filter leaks can also cause such a problem..

 

There is check valve and fuel presure limiting valve (4 bar) on driver's side of engine, under plastic cover near the PLD units.

mercedes really is PLD engine (no pump injectors). Pump units are cam driven (engine is OHV of pushrod design).

EMC is not so voltage sencitive like Volvo ore DDEC-IV and battery power wires are directly connected to starter power supply so if starter cranks engine no low voltage issues (two red wire positive battery power, two brown - gegative battery power, pin 15 on x2 connector - ignition circuit).

 

Good job pichu!!

You taught us all something, THANKS!

 

On a Mercedes make sure the o ring in the fuel filter is installed correctly as well, thought it was the check valve on one I was driving awhile back. Nope moron changing oil missed an o ring. I know yours is already done but so you know kinda thing