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Old 06-02-2020, 05:27 PM
Usaguy Usaguy is offline
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Join Date: Aug 2019
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Quote:
Originally Posted by cleavster View Post
...(1) Fuel Tank Purge/Regeneration valve (107-470-08-93-M22) - this valve is connected to the throttle body, charcoal canister, and to a solenoid switch.
What is the best way to check this? Can I just pull it out? Not sure how it is all connected inside the inner fender...
There are ways to check it.

The fuel tank vent valve is supposed to hold 0.7 psi of pressure and up to 0.5 in-hg of vacuum (not much). Depending on the situation your fuel tank can be under pressure or under a very slight vacuum.

Sometimes what happens is the charcoal canister can get clogged and you will get weird issues like a gas station pump shutting off (happened on my car) or in an extreme case your fuel tank will collapse:

https://www.benzworld.org/threads/screwed-by-a-charcoal-canister.1712285/

This valve is usually located near the rear axle and from there it goes to the charcoal canister and from the canister to the throttle body and some models have a thermostatic vacuum switchover valve on the cylinder head.


Quote:
Originally Posted by cleavster View Post
...(2) Air Pump Check Valve (000-140-78-60-MBZ) - this valve is connected to the engine. It requires a large wrench size and I'm not sure what is the best way to remove and test the valve....
To test it you can check for a vacuum leakage with a vacuum gauge to check for a torn diaphragm.

Of course check the vacuum line routing and an electrical connection to the switchover valve.


Quote:
Originally Posted by cleavster View Post
BTW, battery voltage is at 14.3V when running
That's perfect
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