Mechanics

TOO MUCH FUEL SYSTEM PRESSURE? MERCEDES IT TAKES BOTH HANDS TO GET GAS CAP OFF.

1985 Mercedes Benz 380sl • 94,600 miles

There is so much pressure in the fuel tank that it takes both hands to remove the gas cap. The amount of pressure that is released will blow your hat off. My 1982 380sl doesn't have that kind of pressure and it run better. What do you think? Could this cause the injectors to leak when the engine is off? Could the leaking injectors cause the smoke on start up? Could the high pressure cause any problems?

Thanks.
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Charlestuck
September 6, 2013.



I was asked to see if I can help you out here.

This system is designed to maintain a pressure of 30-50Mbar of pressure. Anything over that is released through a vent valve to the charcoal canister. I would suspect that your has either a restricted line or a defective vent valve.

Here is a diagram of the system. #51 is the vent valve.


Wrenchtech
Sep 6, 2013.