Hi guys,
I have owned my 1988 IROC-Z for three years now and have had a gas oder smell from it since day one. The oder is bad when your intown crusing and is so bad you can not drive with the windows down without getting such a bad oder in the cab you can't stand it. I am not sure but think the smell is comeing from the fuel tank filler neck. It leaves not fuel on the ground but is worse when the fuel tank is full. I was a a GM garage today and they want $408.00 dollars for a new fuel tank but I don't have the money for that. Any sugestions? Has anybody else had this problem? If you guys have any ideas for me let me know. Thanks Dennis

 

Check the fuel cap. Look at the rubber seal and press it with your finger to find cracks. If it has any, replace it. They're only about $5.

Look at the filler neck where it goes into the tank. If the tank's ever been removed, there's a chance the brazing at that joint got cracked during R&R and it's leaking fuel. Look for damp areas around it.

Then, check the charcoal canister. The older canisters are servicable, and have a removable element you can replace in the bottom of it. If the CCP solenoid is bad, it'll leak a fuel vapor smell on shutoff. It'll do that if your VSS is not working, too.

Then look at the intake around the injectors for leaks. Be sure to look at the fuel filter connections under the car to be sure they're snug. Sometimes an o-ring just decides to go on strike, or there's a leak somewhere else on the fuel rail. Just on the fuel rail and upper fuel lines, there's 25 o-rings including your cold-start injector's, 2 threaded connections, a schader valve, and an FPR where there could be a possible leak (that's a lotta possiblilities ).

If you smell it while you're driving around, are you sure it's not just the car running rich? Check the plugs, and/or tailpipes. Or an exhaust leak before the cat? Those smell like gas sometimes if it's a really small leak. A large leak just makes you lightheaded and nauseous. :P

I got a new tank from a junkyard for $30 last year. I say new because it still had the shipping label on it from GM and the car it came from had recently had it replaced with a new unit. Talk about luck, huh?

You could also check the little white pressure valve by the gas-tank. Look at where the fuel lines run along the "rail" and you'll see one line that ends on a funky-looking plastic thing.