I'm glad this subject came up. We (my boy and I) restored an '80 Volare Duster a few years back which he still owns and drives. We have a problem regarding gas tank venting but it is the opposite of the one mentioned in this thread.

Instead of pulling a vacuum in the tank as Kitz mentions, his builds up pressure in the tank. Sometimes after driving for an extended length of time then stopping for gas there is so much pressure it almost blows the filler cap out of his hand (his description). When the fuel level is low and there is pressure in the tank he gets goofy gauge readings, like, it shows to be lower on gas than it really is. Could the pressure be pushing the float down into the gasoline and causing that?

The Volares and Aspens of that era ('76-'80) have a big fancy chrome filler cap instead of having a filler access door. I drilled a small hole through the cap so it could breathe, and that didn't help the appearance of the cap and didn't impress the safety inspection guy one bit. Instead of taking the trouble to solve the problem, I took the lazy way out and bought another cap for him to put on before he takes the car in for inspection.

What do I do now, coach?


Jim