This is a 305 with TPI & 5spd. TPI was just rebuilt. I can smell gas after pulling in garage both before and still after rebuild. I can't find any leaks and don't smell it from under the hood ... but as I get out of car or walk around car. Any ideas of what else to check? Is this uncommon?

 

J,

Check the vacuum lines, vent line, and purge control on the EVAP canister. The canister should be located at teh right front corner of the engine compartment. Check the hose connections against the VECI label on the underside of the hood to make sure everything was connected correctly.

The label should look something like this:



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Later,
Vader
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"Click - Click - BOOM! Saliva - American Outlaw"
Adobe Acrobat Reader

[This message has been edited by Vader (edited September 10, 2001).]

 

Wow ... thanks for all the detail Vader. I'll check it out and let you know if I find anything from you post.

 

Vader ... all the hoses seem to check out OK.
As I walked around the car last night, after pulling into garage, it seems to be most noticeable near the gas filler. The gas cap gasket seems to be OK but the neck where gas nozzle goes seems to be a little loose. I got under car but could not see any visible leaks but could also not actually see where neck goes into tank. I'm still not sure if this is the source ... has anyone else had anything similar.

 

I have the same thing, however, I solved it.
I went to get emmisions tested and they told me I had a leak.
My brother-in-law and I pulled everything, and found no bad hoses. There is, however, a pressure relief valve on our cars. Mine was bad.
Our gas caps do not vent, so an attached device vents for us. It sits just ahead of the gas tank on the driver's side. There is a 90degree bracket and this snaps into it. It is just above the axle where all the fuel lines head up towards the top of the tank.
Every time I stop (parking lot, in the garage etc.) I hear it vent.
If you don't have emmisions that check that kinda thing, don't worry about it. My car runs no better or worse, but I would assume that at some point your SES would light up. I think it cost me $8 at the dealersh!t.




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Chris G
91 TA WS6


See more of her here!
Wise man once say "Red ones go faster!"

 

Thanks Chris ... I'm getting ready to check it out right now. If I understand you correctly, this valve may be stuck open on my car and venting all the time? I'll probably try to fix it if I can as I would hate for someone to walk beside my car right now with a lit cigar in their hand ... its quite a strong odor on mine. Will update on final outcome.

 

try to check the filler tube there was a recall on our cars for the filler tube it had a tendency to crack and vent fumes into the atmosphere. after the canaster that vader reccomended I would check for this.

good luck

 

poncho9798 ... I found the recall you were talking about NHTSA CAMPAIGN ID Number: 94V077000, potential number of units affected were estimated to be 232,988. I'm scheduled to have mine checked out tomorrow at local GM dealer. Thanks for the tip ... with my filler neck seeming to be a little loose I think this might be it.

Canister that Vader mentioned seems to be OK.
Will post the results of inspection.

 

It’s been a while and although I haven’t got the problem fixed yet I now know what it is.

I have a defective gas cap that is allowing fuel to spill out and fumes to vent. Problem was worse when tank is filled and after taking left turns.

I found this by removing the gas cap cover and the rubber fuel neck shield (both simple … 6 bolts and all can be removed right at cap). I did this to be able to view where the neck goes into tank to visually see if it was damp or if I could see a crack when I wiggled neck. To my surprise the neck attachment point was dry but end of neck was very damp and I could see where gas had dripped down from cap to inner fender panel.

I took this route as Pontiac dealership wouldn't inspect car for free because a previous owner had already had the tank replaced under the recall.


[This message has been edited by Jcpstrat (edited October 07, 2001).]

[This message has been edited by Jcpstrat (edited October 08, 2001).]

 

Jcpstrat: I had the same problem getting the chevy dealer to look at my z. They wouldn't do it but suggested the gas cap. Tried that, and I would wager to bet that the smell is WORSE now than with the old cap. I can't figure it out...the tank holds quite a bit of pressure so it's not leaking anywhere, and there are no signs of liquid gas running out anywhere.

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1992 25th Anniversary z28 Convertible

 

TOPLESZ ... Yep these things can be frustrating. As I mentioned I haven't actually solved my problem but I think I'm inching forward even though it seems to be at a snails pace. A new cap didn't solve it, because the opening is out of round ... I'm very carefully and slowly trying to get it back to where it looks like a circle instead of an egg.

 

Hmmm I didn't even think to check whether or not the filler was round or slightly out of round. Methinks I will take a look at that when I get home.

That may also explain why the nimrods at the gas station (full serve here in jersey) can never seem to get the cap on straight resulting in gas pouring out of the filler neck. They get mad when you get out and check that they put it on right

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1992 25th Anniversary z28 Convertible

 

TOPLESZ ... the odd part with yours is that it holds pressure ... mine doesn't. There is also a gas tank ventilator value located under the car behind the driver seat near the driver's side rear wheelwell. It is a one-way valve with filter to allow air to come into tank as gas is removed but does not allow fumes & pressure to escape. If this goes bad I'm told you will smell fumes but you would probably also loose pressure ... mine was OK. It costs around $20 from dealership and is easy to change ... one hose clamp and then pop out of bracket on my 91 T/A but as always with fumes you need to be really careful.

 

When I bought this car, I smelled gas all the time, it didn't matter if the tank was full or empty, I always smelled gas. I remember the presure being held, so that when the tank was close to empty the pressure would hiss out when I would loosen the cap. When the emmisions people told me I had a leak I couldn't even think of where to start looking, so I had a friend come over. We jacked the car almost onto 1 tire (safely) and took my vacuum pump/brake bleeder and started testing all the lines. Every single one, and they all held pressure. All of them except this one that hooked to this 2 inch round plastic doodad, because the doodad's hose nib was broken/cracked just between the end of the rubber hose and the actually part itself. The "pressure relief valve" doodad was less than $20 at the dealership. We put everything back together, I took it down and it passed all the emmisions test (after changing out my crappy AC Delco Rapid-Fires for some Bosch Platinum +4s).

When I park my car, shut the engine off, get out and close my door, the resulting jolt to the gas tank causes the pressure to be relieved, and I hear the little plastic thing go "woosh" for about 1 1/2 seconds. I smell gas after that happens (obviously). If I leave the car running, or don't close my door, I don't smell gas. (BTW I back into the 2 car garage, so I walk right past it) I noticed I had a bit more pressure when I run the tank past a 1/4 tank when I loosen the gas cap, but have never noticed the end of my filler neck wet or any gasoline stains back there.

If you have checked your pressure relief valve doodad thingymcbob and it appears to be working correctly, and you have replaced your questionable gas cap (I have a hard time getting mine on straight occasionally as well...) I can only recommend doing the same thing I did. Get one of these vacuum line tester/brake bleeder (hand pump w/ small plastic cannister underneath and a guage on the top, got mine at autozone or something) plug all but one line into your gas tank at the point closest to the tank, and start pumping. If you can build pressure, your tank isn't leaking, and you have to check the lines. It will take about 100-150 pumps, so don't give up too easily, and it works better if the tank is fuller. Your only looking for the nedle to hold steady, not return to zero. Testing the lines involved tracing each line from the tank to the engine bay, blocking the engine side with a bolt (or a pair of visegrips and a friend)and a couple pumps. Again, looking for the needle to stand still.

If I can help in ANY way, please e-mail me personally, as I got laid off last week and am sitting here at home looking for something to do while I send all these resume's out...



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Chris G
91 TA WS6


See more of her here!
Wise man once say "Red ones go faster!"

 

Chris ... thanks for all the detail and that’s a beautiful T/A. If getting this filler neck round still doesn't solve my problem, I'll definitely try the pump to find out where the loss of pressure is. I'd really like to know how it got out of round ... it looks almost like someone took a pair of vice grips to it ... maybe they lost their keys to the locking top? Good luck on the job hunting.