Author Topic: Evaporative Emission Control System (Charcoal canister)  (Read 20667 times)

Offline jackjeckel757

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Evaporative Emission Control System (Charcoal canister)
« on: November 08, 2011, 08:26:21 pm »
Is it necessary to have the EECS hooked up? When I bought my 77 c10, the charcoal canister was only connected to the fuel tank and the other hose that says "carb" on the canister was connected to nothing. I never really payed much attention to it before but I was curious if it should be connected to anything. I am not running the stock carb or intake by the way and its a 305.

Offline bake74

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Re: Evaporative Emission Control System (Charcoal canister)
« Reply #1 on: November 08, 2011, 08:30:51 pm »
     Depends on where you live and the laws, one way to find out without giving away your truck is go into a inspection station, not driving your truck and ask.
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Offline gto109

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Re: Evaporative Emission Control System (Charcoal canister)
« Reply #2 on: November 11, 2011, 06:34:50 pm »
where i live the Emission laws say must be there and appear to be working.  now the next county over it has to work and they will put a sniffer test on it.  best bet check your local garages.
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Offline 79GMCChris

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Re: Evaporative Emission Control System (Charcoal canister)
« Reply #3 on: November 11, 2011, 11:02:59 pm »
Here's a 79, 350ci, hope it helps.

Chris
Chris
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Offline jackjeckel757

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Re: Evaporative Emission Control System (Charcoal canister)
« Reply #4 on: November 13, 2011, 11:41:52 am »
As far as getting it inspected, the truck has already passed 2 times now as is. My concern was that the Haynes book says if its not hooked up right it could cause mileage & performance loss, although I haven't noticed anything bad yet.
Thanks for the diagram Chris, my '77 doesn't have as much to it with only 2 connections on the can, no air pump, or egr.
From what I figured out the other hose should go to the carb vacuum port, I will try it out and see what difference it makes.

Offline Jason S

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Re: Evaporative Emission Control System (Charcoal canister)
« Reply #5 on: November 13, 2011, 04:54:53 pm »
I think if the evap system is incorrectly hooked up, fuel mileage and performance will suffer.

However, if you can pass emissions without it, you could cap off the carburetor vacuum port and be fine without the canister hooked to the carb.

The charcoal canister is intended to limit fuel vapors from being able to freely vent to the atmosphere, reducing air pollution by VOC's.
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Offline 1980c10

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Re: Evaporative Emission Control System (Charcoal canister)
« Reply #6 on: November 13, 2011, 10:05:09 pm »
I have no emissions stuff hooked up to my engine at all it runs great has good power and great mpgs. I also have no inspection to pass.