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How to test charcoal canister

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tdskip

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Looks like I may be having a fuel venting issue on the TR8, which raises the question of how you check the charcoal canister to see if it is venting properly?
 
Pretty much. There's no moving parts, just some charcoal that's supposed to absorb hydrocarbon fumes and "purify" the air as it passes thru the cannister.
 
Ha - OK Todd. Let me be more specific. On the TR8 there is a line to the carbs, one to the rocker and then a third. Where does the third line go and how much resistance if any if it supposed to have?
 
Gas tank vent ?
if it is, then it should be possible with lung power to blow thru that line toward the gas tank. If you can't then there's a blockage in the line between the gas tank and CC and a vacuum will build in the gas tank as the fuel level drops leading to no gas getting to the fuel pump.
That's the way the TR6 works.
 
That is basically the problem I am trying to troubleshoot Ken.

When I blow on that third line there is resistance. It feels blocked.
 
I've had that twice. Both times it was gasoline in the belly of the vent line from the tank to the CC.
I over filled the tank the first time, in fact got distracted and overflowed the filler neck
Second time, took a twisty with a nearly full tank and centrifugal force sloshed gas into the vent line.
The side of the road solution was to open the gas cap, until I got home to the compressed air
 
Hi Ken - on my TR8 the fuel cap isn't tight enough to actually seal the system, or at least I don't think it is. That said, something is still going on.

I think I need to remove the cap and try blowing through the line again.
 
If you remove that black funny shaped door in the trunk, you will see the gas tank vent filter. It is semi transparent and snaps/slides down into a holder on the body. I'd bet your issue is somehow associated with that. Only you Cali guys have to worry about junk like this. Most TR8 charcoal canisters were removed back in the early 80s when we started installing headers and four barrels. If you need any of that smog stuff, I might still have some kicking around. I'll never use it, so it's yours if you need it.
 
Thanks guys - and Don especially for the tip on mixing fuel and my lungs.

I'll pull that back panel and see what I have back there. Thanks for the offer Todd.
 
I removed the fuel cap and no change in resistance when trying to blow into the tank, so that would suggest the rear venting mechanism near the filler is AWOL. Yes?
 
Sounds more like a blockage somewhere between the CC and the fuel tank..Taking gravity into account, probably in the belly of the vent line, or the low point in the separator or whatever it's called on a Wedge.
 
Hi Ken - yeah, sounds like it. Time to pull the rear vent assembly and see if anything obvious jumps out at me.

Darn Triumph quality, it only worked for 31 years.
 
You tried compressed air into the hose disconnected from the CC, right ? It almost has to be gas, I can't see how anything else can get into the lines.
Unless... was it open or disconnected where a dirt dobber could have gotten in the hose?
 
Hi Ken - pulled the rear vent off and then blew into it and the passage way was more clear, there was some bubbling in the line so some sort of liquid got in there.

My compressor is out at the hanger, but sounds like I need to just blow the line clear.
 
OK - just used the homemade pressure bleeder to blow air through that line and I now get good airflow from the front to the back.
 
Hi guys - quick update. Made it all of 5 miles to PepBoys and back without issue, so it looks like the venting issue was the problem this time. Thanks for humoring poorly asked question about the canisters when I was really asking about venting.
 
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