8 replies to this topic

[nismo1534]

84 carbed CRX. If I fully-seal/seat my gas cap 2 things happen:

 

Excessive pressure in the tank - much more than what is considered normal (I have another 1G CRX and it does not do this)

 

Gas comes out of the vent line in the engine compartment that goes to the charcoal canister and will continue flowing out until I relieve pressure in the tank by removing the gas cap.

 

What is going on here? Is there a line on the tank that is crossed? A bad valve on the tank? At this point, I have to leave the cap unscrewed.

Edited by nismo1534, 01 March 2018 - 02:04 AM.

[Bars84CRX]

I vote you swap the gas caps - see if it goes away.  If it does then buy a new cap.

They should be vented to allow air IN, but not necessarily out.  The air displaces the used fuel or a vacuum occurs.

[Sinub]

I'm not sure on Carb'd gas tanks but on the Si(FI models) we have a two way valve on top of the gas tank. That can possibly be bad. It's easy do take off. No need to drop the tank but maybe lower it a bit, remove the two screws. Blow air through it and see if it just blows through or not. 

[nismo1534]

I swapped the gas caps, but that did not help. The carbed 1Gs have the valve on the gas tank as well. I pulled a working one from a wrecking yard, so installing that will be my next attempt.

[PuddleSkipper]

Drop the tank and inspect the lines, if someone didnt know what they were doing there is a line that runs from the back of the gas tank to the front and ive bent it before. Also there is a rubber hose elbow that if its replaced with a piece of hose it will kink and do the same thing.

[PuddleSkipper]

Drop the tank and inspect the lines, if someone didnt know what they were doing there is a line that runs from the back of the gas tank to the front and ive bent it before. Also there is a rubber hose elbow that if its replaced with a piece of hose it will kink and do the same thing.

[PuddleSkipper]

Drop the tank and inspect the lines, if someone didnt know what they were doing there is a line that runs from the back of the gas tank to the front and ive bent it before. Also there is a rubber hose elbow that if its replaced with a piece of hose it will kink and do the same thing.

[nismo1534]

I forgot to update this thread. I dropped the tank and, sure enough, the previous owner had bypassed the pressure relief valve and crossed the pressure relief line (line that runs to the charcoal canister) and the fuel return line.

 

I hooked up the lines properly and installed a replacement pressure valve. Things are back to normal.

[Sinub]

I forgot to update this thread. I dropped the tank and, sure enough, the previous owner had bypassed the pressure relief valve and crossed the pressure relief line (line that runs to the charcoal canister) and the fuel return line.

 

I hooked up the lines properly and installed a replacement pressure valve. Things are back to normal.

Did you take any pictures? I might need to check mine out.