1988 fuel tank vent line (Page 2/2)
tmadia NOV 29, 06:22 PM
Isn't there an expansion tank in the passenger side wheel well? If so could that be plugged somehow?
Gall757 NOV 29, 06:49 PM

quote
Originally posted by tmadia:

Isn't there an expansion tank in the passenger side wheel well? If so could that be plugged somehow?



Yes, and it is item #7 in the Ogre's first graphic, but only for years '87 and '88. The metal lines run under the battery.

[This message has been edited by Gall757 (edited 11-29-2019).]

James_GT NOV 29, 07:40 PM
87-88 Fuel Expansion Tank - as seen from underneath the car, ahead of the rear-right wheel



I've been looking into this lately, as the source of my fuel vapour leak

------------------
James
RHD '87 Fiero GT

[This message has been edited by James_GT (edited 11-29-2019).]

tmadia NOV 30, 09:53 AM
Anyone know what's inside that tank?
Gall757 NOV 30, 10:39 AM
Air that smells like gasoline. Sometimes there is liquid gasoline if you fill up on a hot day.
tmadia NOV 30, 01:45 PM
That's it? No filters or anything that could clog up? Seems unlikely that that could be the culprit then.
TXGOOD NOV 30, 09:52 PM
Thanks for the comments.
I pulled the tank out today and probably tomorrow will try to clean out the lines.
Tank looks good and someone must have had it out in the past because the front mounting hole has been notched
and I saw a thread that showed someone had done that very thing to be able to slide the tank onto that front top bolt
without having to try to get the bolt started, which would almost seem impossible without taking the rear clip off.
I don`t think the tank has been used for a long time as the vapors smelled really old.

[This message has been edited by TXGOOD (edited 11-30-2019).]

theogre DEC 01, 02:50 PM
I think line part to EVAP can has the restriction above is likely only thing might plug up.
Tank is empty 99+ % of time.
Tank is only a backup expansion tank when main is full and then gets hot or worse some fool pushes pass full when pump nozzle first shuts off.
This was to make main tank and lines to allow ~ 1 gallon more vs older Fiero tanks.
This tank and vent line(s) may have some water in it because any air breath in can/will condense any water in that air.

If the overflow tank was removed...
If replace because old one leaked etc. then maybe didn't clean the "new" one.
If "cleaned" may have done it "wrong" now plugged again. Cleaners and rust removal product can plug the small hole or make small hole smaller after done that plug up easier.
Some use tank coating for main tank that will plug the small hole here too.

I don't know if you can see the small hole. If you can try pushing a small drill or wire thru it to make sure you remove rust etc. Size is likely non critical but don't wallow out the hole either.

Quick EVAP leak test is unplug line to EVAP can then use old tire valve cut to fit the rubber hose so can easily put ~ 6 psi air in the system using a hand pump then monitor air lose. If air is gone after only a 1 minute or 2 then go to a shop w/ smoke test to quickly find it/them. Get a new Gas cap then retest might help and cheaper if that the leak.

Why Bother? Leaking gas fumes is bad enough but that lets water in and causes big problems w/ E10 fuels.
TXGOOD DEC 02, 11:55 AM

quote
Originally posted by theogre:

I think line part to EVAP can has the restriction above is likely only thing might plug up.
Tank is empty 99+ % of time.
Tank is only a backup expansion tank when main is full and then gets hot or worse some fool pushes pass full when pump nozzle first shuts off.
This was to make main tank and lines to allow ~ 1 gallon more vs older Fiero tanks.
This tank and vent line(s) may have some water in it because any air breath in can/will condense any water in that air.

If the overflow tank was removed...
If replace because old one leaked etc. then maybe didn't clean the "new" one.
If "cleaned" may have done it "wrong" now plugged again. Cleaners and rust removal product can plug the small hole or make small hole smaller after done that plug up easier.
Some use tank coating for main tank that will plug the small hole here too.

I don't know if you can see the small hole. If you can try pushing a small drill or wire thru it to make sure you remove rust etc. Size is likely non critical but don't wallow out the hole either.

Quick EVAP leak test is unplug line to EVAP can then use old tire valve cut to fit the rubber hose so can easily put ~ 6 psi air in the system using a hand pump then monitor air lose. If air is gone after only a 1 minute or 2 then go to a shop w/ smoke test to quickly find it/them. Get a new Gas cap then retest might help and cheaper if that the leak.

Why Bother? Leaking gas fumes is bad enough but that lets water in and causes big problems w/ E10 fuels.



Thanks, I`m going to replace my fuel sending unit and fuel pump in a bit.
I will check all of the lines then as I do want it to operate the way GM intended.