On the 73-87 trucks there is a vapor line that runs from the fuel tank out to the radiator support which connects to the vapor canister, make sure that is connected. Gas fumes will com out of that line if it is open.
Also Check the float level on your carb. Holly's arent always ajusted out of the box. Some times the float level on the secondarys are a little too high, while at an idle gas will drip into the secondarys & you will get a gas smell from that.
Pull the sight plugs out each float bowl & check the fuel level.
If gas pours out of the hole, then the fuel level is too high.
The fuel level should be level with the bottom of the hole.
If you do need to adjust them, there is a 5/8 lock nut with a screw in the middle on the top of each float bowl. Undo the screw & turn the nut to raise or lower the fuel level.
But like everyone else says first check for leaks. Also check any rubber fuel lines. Ethanol raises hell with the older rubber fuel line material. Any new rubber fuel line that is sold today, supposedly is compatible with Ethanol.
Good luck, let us know what you find.
Last edited by JeffL; 03/23/2013 6:57 AM.
