[TR] help needed with persistent gas smell

[Reihing, Randall S.]

You might try to see if a fuel compatible dye is available and use that, then look for the color. As an alternative, aviation fuel, for example, is color coded. The new 82UL av gas for low compression engines is dyed purple. The 100LL (Low Lead) av gas is blue and 100 octane with the normal amount of lead, is green.

As a suggestion, run the TR3 until the tank is dry, or drain it, and then fill with 5-10 gallons of commonly available, blue 100 LL at your local county airport and fill the TR3 tank with that. This is not cheap gas.Most 100 LL is around $5.25/gallon so if you only buy 5 gallons it might be a good idea to make sure the TR3 tank is empty first so you don't dilute the color. Then use some white paper towels to look for blue stains around the outside of the tank.

Don't be concerned about the 100 octane being more than the TR3's required octane. It cannot harm the engine and if the engine still has the original valve seats, the lead will be beneficial. If the engine has the newer hardened valve seats, the lead will not be an issue.

Other thoughts: Any chance the fumes might be a leak from the fuel pump if the car still has the older stock fuel pump with the primer handle? Or maybe an overflow from the carburetors that would only occur while the engine is running? For that last one you have to observe the engine while it's idling and watch for drips exiting from somewhere around the carburetors, perhaps dripping onto the floor.

Hope that helps.

Randall S.
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From: Triumphs [triumphs-bounces at autox.team.net] on behalf of Kinderlehrer [kinderlehrer at comcast.net]
Sent: Sunday, October 01, 2017 7:08 PM
To: 'TR3 Triumphs'
Subject: [TR] help needed with persistent gas smell

My brother is really enjoying the TR3A he bought several months ago, except for the smell of gas in his garage every morning. The car was recently restored but he had all the fuel lines and carburetors checked by a British car mechanic shop. He had the overflow blocked to no avail, I convinced him to replace the gas tank suspecting pin hole leaks at the bottom and that didn’t help either. The smell is strongest inside the trunk so I suggested that he blow up a balloon inside the filler and see what happens. No smell so he had the hose from the filler to the tank replaced, but the smell returned. Next he covered the filler with a plastic bag, The smell went away but if he took it for a short drive with the bag in place, the smell returned after he parked the car in the garage.

Other than replacing the filler cap, I am out of ideas. We considered plugging up the vent hole in the filler cap, but he won’t be able to drive very far like that. Has anybody struggled with this issue and found a solution? Anyone have any ideas on what might be going on here?

Thanks for any help,
Bob
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