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Please identify the coffee can thing[700/84] posted by Joshua Block on
Friday, 17 September 1999, at 3:24 a.m.
I'm trying to hunt down any vacuum leaks in my 84 760 Ti and have a
question about a part.
There are two small diameter vacuum hoses that come off of the top
or the throttle body and connect to the top of a black plastic coffee
can looking thing buy my battery (driver's side) There is also a one
foot piece of 3/8 hose that hangs from the bottom of the can and w
does not connect to anything. Inside the can is what looks like a
filter of some sort and is yellow.
What is this can and should the bottom hose connect to something?
Is it an air intake for the throttle? Why are their two vacuum hoses
running to the same thing.
BTW - this can is missing from the underhood view at the beginning of
the Haynes manual. The nipples on the throttle body appear to be
capped off also. I've seen something that appears to have the same
funtion mounted diagonally under the battery/bumper of a 240.
Joshua
Yes...charcoal canister, evaporative emissions[700/84] posted by JohnB on
Friday, 17 September 1999, at 11:28 a.m.
It doesn't break down the vapors, it simply stores them, adsorbs them onto the charcoal, during periods of high emissions and then the engine sucks the gases out of the canister during cruise and burns them.
The valve on the top of the canister can fail, leading to a lean running condition during cruise, and/or a lean idle depending on whether the car in question is ported vacuum to that valve. One line leads to the evap emissions separator for the gas tank, two lead to the throttle body, and the one on the bottom is a drain to the street in case the canister gets overfilled (which is why you're not supposed to 'top up' your tank when you fillup...not to mention don't do it while the engine is running...the excess fumes just plug the canister.) On a lot of newer cars, overfilling the tank can lead to a slug of engine fault lights and subsequent trips to the dealer to turn the darn things off, even though the canister corrects itself most of the time.