When the solenoid activates, it turns off all posible fuel, not just killing the ignition. An engine without fuel will not run on.

My first thought here was what Steve said. Take away the fuel when you turn off the engine.

------------------
Benzmac:
Donnie Drummonds
300E
ASE CERTIFIED MASTER AUTO TECHNICIAN
MERCEDES SPECIALIST 8 YRS
PARTNER IN MERCEDESSHOP.COM
OWNER OF MB AUTOWERKS .COM