Last night I stopped for fuel and ended up spilling a bunch of gas on the ground. I shut the car off and put about 6 gallons in the tank. I left the cap loose because I wanted to put some gas dry in since it is cold here and my car is sitting for several weeks at a time. I did not "top it off" or over fill the tank. I went in to pay and forgot the gas dry. I came out looked down at the cap and gas was coming back out of the filler neck and onto the ground. 1-Why was it doing this? The car has ran poorly a couple times and I assumed it was bad gas because when I put more in it would then run fine. 2-Could just removing the cap and replacing it have corrected this? When I put the engine in this summer I plugged the return line to the tank. 3-Should this be vented instead? It does hiss some when the cap is removed. I am running a holley street mechanical fuel pump. The car runs great usually and was running fine before and after I stopped for gas.

------------------
350 Vortec, forged flat-tops, CompCams XE268, Edlebrock RPM, Holley 3310, TH350 w/Holeshot 2400, 3.23 posi, Heddman shorties, HEI

 

Eric,

The return line should be connected to the tank fitting or you can artificially generate high fuel pressure under some circumstances. This could lead to flooding the engine, flooding the EVAP canister. There should also be an EVAP canister to allow the tank to vent the excess pressure without surging raw fuel out the filler cap relief valve (your last safety in the system).

------------------
Later,
Vader
------------------
"No matter how hard you try you can't stop us now"
Adobe Acrobat Reader 4.0