Evap System Problem?

[cwarrenburgess]

I have a 1993 Chevy Suburban with a 7.4 454. I have noticed a strong smell of old fuel (described by a friend as "junkyard fuel") coming from under the hood when the engine is running hot (220-240) and the hood is shut. When I shut off the truck and open the hood, the smell is very strong right around the evap canister and nowhere else. When the truck is running cool (180-210) there is no smell at all. My fuel ecomony has also dropped over the past two weeks by approximately 3mpg. Is my evap canister bad, or could I have a leak in that area?

[redvett]

Your vapor canister is bad and not capturing the gas vapors. Have you checked the hoses to engine and canister? Replace the canister if lines are good and fuel economy should return.

[cwarrenburgess]

Thanks! I was hoping that was all it was. That is an easy enough fix. I bought new rubber fuel line and an evap canister today and will check the lines as well as replace the canister and any rubber fuel line along the vent path from the tank to the canister. I will post the results as soon as work is completed. Thanks again for your advice.

[Bluedog]

Thanks! I was hoping that was all it was. That is an easy enough fix. I bought new rubber fuel line and an evap canister today and will check the lines as well as replace the canister and any rubber fuel line along the vent path from the tank to the canister. I will post the results as soon as work is completed. Thanks again for your advice.

 

Also, be careful you don't overfill the gas tank, especially now that summer is here. Liquid gas can backflow into the canister and ruin it. Had that happen to a '95 Blazer that I had a couple of times until a mechanic told me about the problem. Never did it again.