I did some searching and found out the 69 had a factory vent for the gas tank besides the vented cap. I am having presure build up on my car and was thinking about putting a factory type vent on my tank. Its a repo so it has nothing. I looked in my i parts guide but the 69 fuel system was not shown. Does anyone have a picture or diagram they can post or send me. Thanks Steve
1968 Firebird 1969 Firebird project Routy Watch the build
Steve, from what I recall, this was a change made on all 1969 Firebird gas tanks. What's happened over the years is that probably 50% of all the 69 Birds that ever had a gas tank replaced (in the 70's, 80's, etc) used the GM replacement, which was a Camaro tank, and that tank did not have the vent. Also, since the aftermarket supports Camaros first, 1969 Camaros gas tanks were a very early reproduction item. As usual, reproduction houses used the standard 'fits Firebird too', and while the tank fits, it's incorrect.
Pontiac added the vent due to the low angle of the filler. On hard acceleration, fuel would spill from the gas cap vent. Pontiac remedied this by having a lengthy metal tube (quite elaborate actually), as a vent. I still joke with some friends of mine (that love Camaros) that the reason Chevrolet didn't use the vent was because 1969 Camaros couldn't accelerate fast enough to make it an issue.
This pic is from an old thread on the PY site. On my car (original tank), I STILL had a little spillage on a hard launch, so I had to actually extend the end of the tube, where it pokes out the trunk at the rear panel. I added a rubber hose extension so it comes out at the bottom of the valence. Without that extension, fuel would sometimes spill out the back of the vent tube, then get on the bottom of the rear bumper.
