Help! S55 AMG Kompressor won't start.
 

2003 W220 S55 L AMG Kompressor

Driving along and I lose all response from the accelerator pedal. As I pull in to the side of the road it sits idle fine so I pull away again. 5 minutes later it happens again only this time when I stopped so did the engine.
It hasn't started since. Just turns over.
No warning lights.
No fault codes (cheap generic obd reader).
Plenty of battery power.
Camshaft position sensor replaced (didn't solve it).
Getting spark and power to the injectors but no fuel pressure.
Fuel pump relay and fuse beneath rear seat are fine.
Fuel pump under car doesn't get any power with ignition on.

What next?
Is there any other relay or something else prohibiting power getting to the pump? Google tells me the AMGs have another pump relay but I can't find any details on location.

Any help much appreciated.

Crank position sensor

Agree. Crank Position Sensor is a small hull effect sensor monitoring the magnetic pulses of the flywheel spinning near its tip.

Is that what you meant by "camshaft position sensor?"

"Getting spark and power to the injectors but no fuel pressure.
Fuel pump relay and fuse beneath rear seat are fine.
Fuel pump under car doesn't get any power with ignition on."

When key is placed in the "on" position, the ECU applies power to the pump for approximately 1 second to pressurize the fuel rail, then cuts power to the pump until the ECU receives CPS pulses indicating the engine is turning over or running (safety feature in the event of an accident).

I'm not familiar with the S55K but here are some related items to consider...
In the W211 E55K AMG series, the issue is clogged fuel filter causes pumps to draw too much current and eventually the fuel pumps and relay fail. On the W211 E55, the relay is NOT in the location indicated via internet searches; the relay is located on the passenger-side of the trunk (left-hand drive) and the paneling must be removed as there is no access port. Examples: the fuel pump relay in an E350 is the heat exchanger pump relay in an E55 and an E350 secondary air injection pump relay is the E55 oil cooler fan relay. So...folks confirm a relay is good but it is not the relay they think is is!

Ensure you have found the correct relay and replace it. They're inexpensive. Depending upon mileage on your car, replace the fuel filter and pumps (I'll do so every 60,000 miles now even at $1000 a pop).

Here are some threads dealing with our issues:

https://mbworld.org/forums/w211-amg/...ng-my-car.html

https://mbworld.org/forums/w211-amg/...lacements.html

You should post a link to this thread in the S55 portion of the AMG sub-forums.