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Fuel leaking from carbon canister

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Don_Houston

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1976 TR6 - Yesterday I attempted the first start-up in 30 years. Using starter spray on three starts (to pull the first fuel into the system?) it stayed running and leveled out at a nice idle.

Then I could walk around the car and noticed fuel coming out from under the emissions carbon canister. I checked all of the hoses there and tried again. Looks like the fuel is coming out of the anti run-on valve. I have previously completely replace the supply and return fuel lines.

I have not touched the carbs at all. Any ideas on root-cause?

Exciting day nonetheless.

Thanks!
 
Carb needle valve(s) stuck open. You're gonna have to rebuild at least the rubber portions of the carbs after 30 years - jeeze, I'm surprised it ran. I would pull the carbs for that, remove the needle valves, soak in solvent and get them working again with fingers. Don't throw them away yet! New needle valves are inconsistent in manufacture & generally suck. The older ones can probably be made to work fine, especially if old style with the screen, and I know several people that prefer them. I use Grose jets, but let's not go there... Rubber portions are diaphragm, shaft seals, o-rings in bowl, ect. Go to the Buckeye Triumph site if you feel a tutorial is in order. Have fun!
 
Weird, I would have sworn I posted a reply to this but it's not here.

Anyway, most likely you have a float valve that is not shutting off the flow of fuel into the float bowl(s). The float bowls are vented to the carbon canister at idle, so fuel is flowing through the vent line and through the canister.

Most likely a piece of crud caught in a valve, blocking it partially open. Could also be a float that doesn't float, or too much fuel pressure (if the pump was replaced). Or could be a float valve that is simply too worn to seal properly (although that very rarely happens in my experience).
 
Thanks. Sorry for the double posting. I kept checking the first posting and did not see any replys so I figured I did something wrong. I though that keeping it on the previous thread was good to follow everything I am doing to refurbish the car.

I will start with a carb rebuild kit. The fuel pump is new - are you suggesting that it might be different from the original?

I saw on some posting about putting an in-line fuel cut off valve to make it easy to replace the filter and other downstream stuff. Has anyone used one and where did you buy it?

Thanks!
 
Don_Houston said:
Thanks. Sorry for the double posting. I kept checking the first posting and did not see any replys so I figured I did something wrong. I though that keeping it on the previous thread was good to follow everything I am doing to refurbish the car.
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No worries, Don, and Thanks, Terry. Just having one of those days I guess. In general, I feel it is better to start a new thread for a new question as there will be some folks who checked the original thread, decided they had nothing to say, and won't check it again. Starting a new thread maximizes your chances of getting responses, plus makes it easier for others to find the information if they are having the same problem.
<div class="ubbcode-block"><div class="ubbcode-header">Quote:] The fuel pump is new - are you suggesting that it might be different from the original[/QUOTE]A possibility, yes. ZS carbs require a lower fuel pressure (1.5 to 2.5 psi) than many other carbs do, too much pressure will force the float valve open and flood the carbs. Generally the only difference in the pump is the spring inside, sometimes they get put together with the wrong spring. There's a procedure in the workshop manual for checking it.
https://www.harborfreight.com/fuel-pump-and-vacuum-tester-93547.html
<div class="ubbcode-block"><div class="ubbcode-header">Quote:]I saw on some posting about putting an in-line fuel cut off valve to make it easy to replace the filter and other downstream stuff. Has anyone used one and where did you buy it?[/QUOTE]
Sorry, I can't help there. My TR3 still has its factory shutoff valve, and the Stags have the filter & pump mounted above the level of the tank (so don't need a valve).

PS, I would be careful that the valve you use is rated for enough fuel flow. While poking around fuel valves online, I came across one that has 5/16 hose barbs (so would fit nicely) but is recommended only up to 300cc. You certainly don't want one that will restrict fuel flow (causing a lean condition at full throttle).
 
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