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Discussion Starter #1
This is mainly to satisfy my curiosity. When the charcoal cannister is pulled, do you leave the intake hose from the tank to the manifold active? I'm only asking because it would seem to me that installing a fuel filter on the fresh air side of the tank would be a good idea. That way any debris would be captured by the filter before it enters the tank. In other words, just replace the charcoal filter with an inline fuel filter. Anybody tried this?
 

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Dean, wouldn't replacing the cannister with a fuel filte3r cause EXACTLY the same issues? over filling the tank would cause raw fuel to pass through the filter and make its way down to the fuel rail which would cause the stalling driveability issue?

Loren
 

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Dean,
The hose from the tank is exhaust. It is placed low so any overflow goes to ground. The hose from the air box is capped because it sucks, or whatever!
 

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Discussion Starter #4
My understanding of the original system is that the charcoal cannister collects extra fumes from the gas tank. These are generated any time the fuel in the tank is warmed, such as filling in the summer time when the ground temperature is cooler than the outdoor air temperature or when the cycle is parked with a warmed up engine. When the engine runs, air is drawn up through the filter and into the intake manifold where the fumes burn off as part of the ignition process.

The charcoal filter clogs either with liquid when the tank is overfilled or when the end of the tube under the right side case is clogged with an insect nest or other debris. This is what causes the vacuum effect on the gas tank that can suck the sides in enough to damage the fuel sending unit.

That's why I'm thinking that modifying the cannister removal might be in order so that replacing the cannister with an inline fuel filter would have two advantages. First, it would allow any liquid overflow to pass through onto the ground instead of being captured in the charcoal and second, it would filter the air being drawn into the manifold after the cannister is removed. That's why I was wondering if the basic functions of the EVAP system were being left intact when people were removing the cannister.

This idea hit me when the engine light on my Dodge truck came on with a purge flow fault. That's when I found out that the intake air on the Dodge system has an air filter on it. My guess is that other systems do as well. Otherwise sucking fresh air through the fuel tank regularly sooner or later will introduce a bunch of debris into the fuel and could probably lead to clogged injectors..
 

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Wrencher Extraordinaire
2005 K1200LT
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14,248 Posts
Just plug the line to the engine as there is no need for it if you remove the cannister. (It no longer has a need to suck...) If you want to filter the air that goes back into the tank then do so. But I think it is over kill.
 
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