You can actually see it through the vent on the fender.
1979 gas cap
Thread Starter
Safety Car
Joined: Feb 1999
Posts: 4,043
Likes: 342
From: Central NJ
1979 gas cap
Does the gas cap for a 79 actually do anything? The reason I ask is some years are vented and some are not. I still have the original one and was wondering if there was any benefit to changing it.....Right now I have a fuel pressure gauge on the car and it seems to drop down to about 3 1/2 at the end of the 1/4 mile.....I also have one of those clear fuel filters and for some reason the gas empties out of it after I shut the car down. A few minutes later it will fill half way up...Is that normal?
Thanks....
Thanks....
Race Director
Joined: Sep 2004
Posts: 11,874
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From: Arlington Va Current ride 04 vert, previous vettes: 69 vert, 77 resto mod
well the fuel system on a 79 did not vent to the outside directly because of smog regulations. do you still have the charcoal cannister hooked up? you say the pressure drops down to 3.5 what does it start at? and when you open the gas tank cap after the 1/4 mile run do you hear air being sucked into the tank?
Thread Starter
Safety Car
Joined: Feb 1999
Posts: 4,043
Likes: 342
From: Central NJ
Bob,
I have no idea where the canister would be. The pressure starts anywhere from 5 to 6 and ends up with around 3.5. I never tried to unscrew the cap after a run. Am I correct in saying the cap is sealed and there is no way one can go bad?
I have no idea where the canister would be. The pressure starts anywhere from 5 to 6 and ends up with around 3.5. I never tried to unscrew the cap after a run. Am I correct in saying the cap is sealed and there is no way one can go bad?
Melting Slicks
Joined: Jul 2004
Posts: 2,577
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From: Long Island New York
Race Director
Joined: Sep 2004
Posts: 11,874
Likes: 263
From: Arlington Va Current ride 04 vert, previous vettes: 69 vert, 77 resto mod
well they go bad when they are no longer sealed but thats not your problem.....you may have a blocked vent line some where and actually having a vented cap may help you out
Le Mans Master
Joined: May 2002
Posts: 5,086
Likes: 786
From: Lebanon Township New Jersey
The evap emissions canister is to filter vapors going out of the tank, right? Like when the car is parked, hot weather, and gas evaporates. How does air get back into the tank when the engine is running? My cap doesn't appear to be vented. I have my tank out now just to check it. It looks OK, but I'm trying to figure out why, sometimes, making a pass at the track, the engine will die out and almost stall, but after I let off the gas, it recovers completely. (I didn't think of removing the cap to see if vacuum had built up.)
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From: CORVETTE 77 385 C.I. TEXAS
...Right now I have a fuel pressure gauge on the car and it seems to drop down to about 3 1/2 at the end of the 1/4 mile.....I also have one of those clear fuel filters...
Originally Posted by BKbroiler
I know this is a stupid question - Where is the cannister on a 77?
Race Director
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From: Arlington Va Current ride 04 vert, previous vettes: 69 vert, 77 resto mod
