hissing gas
Team Owner
Joined: Aug 2000
Posts: 40,156
Likes: 45
From: San Pedro CA
Re: hissing gas (1990CORVETTE)
Vettes use a pressurized fuel system.
one of 2 thinks will cause that hissing... 1) the gas cap has a leak and is venting or, 2) one of the return lines, that vents the vapour pressure out into a charcoal canister is blocked, increasing the pressure in the tank.
the canister is next to the tank... sadly, behind the bumper... :(
good luck! :cheers:
one of 2 thinks will cause that hissing... 1) the gas cap has a leak and is venting or, 2) one of the return lines, that vents the vapour pressure out into a charcoal canister is blocked, increasing the pressure in the tank.
the canister is next to the tank... sadly, behind the bumper... :(
good luck! :cheers:
Team Owner
Joined: May 2002
Posts: 24,337
Likes: 25
From: San Diego , CA Double Yellow DirtBags 1985..Z51..6-speed
Re: hissing gas (1990CORVETTE)
The tank should vent to the cannister or to the crankcase vent lines into the intake.
Sounds like you might need a new gascap, but that's not the fix... check your vapor cannister lines (on my 85 the vap cannister is located in front of the drivers side front tire, under the headlight.) It's really easy to get to. It's the cylindrical thing with two rubber lines going into it. the system consists of a vapor purge solenoid, and two vacuum actuated valves. When the valves have vacuum, they're open, otherwise theyre closed. Get a hand pump and pull a vaccuum on these, and see if you can blow through em.
I blew through my two fuel vapor lines (back toward the tank, and into the pcv system) and it cleared them out. That vapor purge solenoid doesn't allow engine vacuum to those valves until the car is above a certain speed and temperature I think.
Sounds like you might need a new gascap, but that's not the fix... check your vapor cannister lines (on my 85 the vap cannister is located in front of the drivers side front tire, under the headlight.) It's really easy to get to. It's the cylindrical thing with two rubber lines going into it. the system consists of a vapor purge solenoid, and two vacuum actuated valves. When the valves have vacuum, they're open, otherwise theyre closed. Get a hand pump and pull a vaccuum on these, and see if you can blow through em.
I blew through my two fuel vapor lines (back toward the tank, and into the pcv system) and it cleared them out. That vapor purge solenoid doesn't allow engine vacuum to those valves until the car is above a certain speed and temperature I think.
