porscheEH!

Everytime I fill up my car or take the gas cap off the tank lets out a bunch of pressure, are 944 supposed to do this or do i have a plugged vent line or charcoal canister?

billthe3

No help to offer, but my camry does this as well. Gets a lot worse/there is a LOT more fumes when the car/tank/weather is hot. So I'm interested in knowing if this is at true problem or normal behavior.

jtsporsche

i kinda like the smell of gas so it dosnt bother me

Bri Bro

There is a vacumm valve that opens up when the engine is started and pulls the fumes out of the carbon canister/ gas tank into the intake where it is burned in the engine.

billthe3

So there should not be pressure in the gas tank?

Bri Bro

When the car is running or has run, it should have every little preasure. If it is sitting in the hot sun of a while with the engine off, it will have preasure.

porscheEH!

hmm no, it only has alot of pressure after you've driven for a bit. I was just worried it might dent the tank out or god forbid blow up lol with all the pressure in there.

Bri Bro

The valve is on the drivers side next to the firewall, make sure the vacuum line is attached to it.

Rock

My yellow car did this all the time when I ran its *** down to the gas light

porscheEH!

Just OB of the Brake Vacuum assist drum?? i thought that was the Clutch MS ?? do you have a picture?

Bri Bro

Here you go.

ritzblitz

My car does it too. Only after its been sitting though. Not after driving.

Keithr726

I've had two of these cars and never experienced something like this. I hope not to, as I'm not up for surprises while filling up.

jtsporsche

the big pointy thing???

Bri Bro

The pointed metal valve is the shutoff valve. It connects to another valve that is a big plastic valve called the Control valve. The control valve is about a inch away from the shutoff valve. Make sure he vacuum lines are connected to both of them and here should be vacumm on both line with a warm running engine.


If you don't have vacuum on the Shutoff valve, check the Temperature valve that opens the Shutoff valve. It is connected to the back water port that bolts to the head. It has two vacuum lines on it, one goes to the throttle housing (always has vacuum) and the other goes over to the Shutoff valve. When the engine get above 130F, the temp valve opens and allows vacuum to got to the Shutoff valve. This opens the shutoff valve and pulls fumes through the Control valve that is connect to the Active Carbon tank. The active carbon tank connects to the gas tank.