I have a 97 blazer and when the truck is running there is a strong smell of gas coming from under the truck it don't leak any fuel but i am also getting bad gas mileage any ideas please help

 

Check to see if the shrader valve on the fuel test port is leaking. They sometimes come loose and bubble a small amount of fuel.

 

ive never heard of the shrader valve do you have any info on it pics or diagrams that would def help also i was looking around the gas tank and there is a hose thati dont know where it goes or comes from look like it might come from the top of the tank where can i find a diagram of the fuel lines ?

 

You have a different motor then me. It should be on one of the two fuel lines that come up on the drivers side under the hood before they enter the plenum. There may or may-not be a screw on plastic cap. Looks kind of bullet shaped if there is no cap. The valve itself looks the same as the airfill on a tire. Check it with the key on. They just kind of seep. Sorry can't help on the fuel lines. Plenty here on them, mostly under fuel pump change. Use the google engine on BF main page.