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Discussion Starter · #1 ·
The gas smell finally got to be unbearable and I traced it to a hairline crack in the black tank behind the cabin next to the jack called a ...

Vapor recovery tank
Vapor recover tank
Fuel canister
Vapor canister

Or any number of other names including "thingamajig." It's a very small (1/8") crack near the seam on top of the tank. I've searched for the part at all the usual places but I'm not finding it, at least not for a 1991 Veloce.

1. What the heck is the part officially called?

2. Can (or should) I repair it somehow? I've never had any luck trying to repair any pressurized part, or

2. Where can I find a replacement part? I couldn't find it on eBay nor IAP.
 

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Sorry to hear about the cracked canister. That smell is a terrible and kills a great ride.

I wouldn't try to repair it.

Larry at APE (Alfa Parts Exchange) has to have that part. Its not one that a lot of people are looking for.

Alfa Parts Exchange - Used Alfa Romeo Parts

Good luck,

Vin
 

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But Mad North-Northwest
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If you get one from APE make sure they give you the later S4 one. It doesn't have the problematic metal tube that was in the earlier ones...it's just a hollow tank.

But like Eric said I bet you can probably just fix it. It doesn't need to hold much pressure. Nothing really sticks well to polyethylene, but I bet if you used some Goop brand sealant it would hold well enough if you made sure to get it all the way through to the inside of the tank.

A hot plastic welder would work well too, but most people don't have one.
 

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Hi you can fix the crack by cleaning and sanding the area in preparation for a small fiberglass patch repair, I use to fix plastic hydraulic tanks using this method. Mind you this was supposed to be a temporary fix till the customer got in the new tank to fix it properly. I do remember a guy who came in a year later bragging how good the repair was holding up. We told him it was supposed to be a temporary not a permanent fix. He said he will fix it when he is ready, never did.
 

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Tank pressure

Forgot. To ask did you have excessive fuel tank pressure before this leak was found? Just thinking symptom cracked tank, cause high fuel tank pressure, kinda just when through something similar myself.
 

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Discussion Starter · #7 ·
Thanks

I'll try a temp fix with fiberglass since I happen to have one on hand for my boat. I'll check in with APE to see of they have the S4 tank/canister.

As for excessive tank pressure, I don't thing so. But I overfilled the tank and this leak immediately followed so that likely had something to do with it. Maybe that caused excess pressure?

The car is running like a dream otherwise.
 

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Hi, what I was asking was when after driving the car for a while did you notice a gush of air when removing the fuel filler cap, gas. Cap? Before the gas fumes smell issue? Might be the cause, the reason I ask is because those tanks are built quite well, anyways good luck and let us know what you find out. Neil.
 

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Discussion Starter · #9 ·
Some air gush when I remove the gas cap but that's never been a problem before nor with other Alfas I previously owned. Nothing out of the ordinary. It could be just a defect that finally showed up. Like I said, it's just a less than 1/8" hairline crack starting at the top seam. I'll get working on later this week. Thanks.
 

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Discussion Starter · #10 ·
Tank / Canister Repair Fail

Just an update. I sanded and repaired the small crack and it held for short drives. Yesterday I took a 300 round trip drive (high desert mountains so warm to hot) and when I got home I was starting to smell the gasoline again. I checked the tank and the repair was still holding, but a new crack developed on another spot on the seam. So it looks like a new tank is my only option.

There is no excessive pressure in the gas tank. Yesterday when fueling up I had no air/vapor gush and last night nothing more than a whisper. Is there something else that could be causing this besides a flaw in the vapor tank? I'd hate to install a new one and then have it crack again.
 

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But Mad North-Northwest
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Well, you won't have any pressure in the tank because it's all leaking out that new crack!

Either you've got a really poorly-made vapor separator tank, or your vapor recovery system is plugged and causing excessive tank pressure. There's a black/white plastic check valve that connects to the hose forward to the carbon canister. I would take this out (note the direction it goes!) and make sure air can flow through that tube to the canister.

You can also *carefully* pop the valve apart to clean it out. The valve is a little weird. It actually flows air in both directions, but it's designed to hold 1-2 PSI in the tank so it's got resistance in that direction. So if you blow through it in the forwards direction (towards the carbon canister) it should open but will take a little bit of breath force.
 

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Discussion Starter · #12 ·
Thanks, Tom. I'll check the valve and overall the entire system to look for obstructions of any kind.
 

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Info about Valve

Well, you won't have any pressure in the tank because it's all leaking out that new crack!

Either you've got a really poorly-made vapor separator tank, or your vapor recovery system is plugged and causing excessive tank pressure. There's a black/white plastic check valve that connects to the hose forward to the carbon canister. I would take this out (note the direction it goes!) and make sure air can flow through that tube to the canister.

You can also *carefully* pop the valve apart to clean it out. The valve is a little weird. It actually flows air in both directions, but it's designed to hold 1-2 PSI in the tank so it's got resistance in that direction. So if you blow through it in the forwards direction (towards the carbon canister) it should open but will take a little bit of breath force.
Hello, I am troubleshooting too, and would like to find out if this valve is fitted right. Assuming there is an arrow on it, which way should it point to? In my case it is an iron one, a little thicker than the tubes itself. Many Thanks
 

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That one-way valve is meant to prevent a vacuum from forming in the tank. Therefor, it should let air IN, but not out. Any out-pressure vapor should go up to the intake manifold and be burned. The fuel tank should operate pressure neutral (Spica models, not sure about L-Jets/Motronics). If there is a vacuum or pressure in the tank when you remove the cap, something's not working correctly.

The valve you're talking about is a small plastic one-way valve. Suitable replacements are available in just about any auto parts store. Something like this: http://www.ebay.com/itm/4-pcs-3mm-I...726?pt=LH_DefaultDomain_0&hash=item19fc9590a6
 

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Hello, I am troubleshooting too, and would like to find out if this valve is fitted right. Assuming there is an arrow on it, which way should it point to? In my case it is an iron one, a little thicker than the tubes itself. Many Thanks
If you've got the metal valve you must have an S3. The S3 used a metal inline check valve to control flow to the carbon canister. The arrow should point from the black tank towards the tube that leads to the front of the car.
 

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Video

Thanks a lot. yes its an 88 USA Spider. ( it has both this metal inline check have as the one way inlet to prevent vacuum) For everyone dealing with this; this video can be very helpful :
 
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