i have a 1985 trans am with a 305 tpi.I have been having a problem where when the car gets hot it makes this loud howling noise coming from the back of the gas tank.At one time it made the car backfire and didnt want to stay running.i was told to change the fuel pump so i did.a few days later the noise came back.i was told to also change the gas vent valuve did that to.nosie came back.i am from las vegas so it gets very hot here so i dont know if the heat has something to do with it.this is making me crazy.most of the time it happens when the a/c is on.but the car runs fine has all power and doesnt seem to be a problem.if any body can help please let me know thanks for your time.

 

is teh howling noise constant at idle and other engine speeds or does it steadily increase with vehicle speed? If you think its a pressure problem in the tank, leave the gas cap off. That will ensure the pressure is atmosphiric at all times. This will definatly tell you if its a venting problem.

 

it does it when the car is running at idle or when i am driving.after i shut the car off i open the gas cap and there is alot of back prussure.so i dont know maybe the gas cap is no good any more info would be great.
thanks
kyle

 

sounds like there is a blockage in the vent like that prevents it from venting properly. Mine does this too and i havnt gotten around to fixing it yet.

 

live in vegas , and have the same problem , just switched mine over to TPI and have this problem. But mine shuts my car down after a long drove , Once I open the gas cap a little and it vented vapor out for like 2 minutes. Not that little vapor at the gas station. but afraid to unscrew it all the way. Short term fix ( not all that safe is to remove the pressure vent all together. you may smell gas a little but better than having your tank blow up from pressure.






91 Rs ( Now TPI)

 

Also, do you keep a full tank of gas? The pump likes to stay cool, and if it's submerged in gas, it'll stay cooler, and last longer. If you're driving around with 1/4 tank or less, that pump's getting hot!