under-hood gas smell?

I parked my 91 Z71 in the garage last nite (usually occupied by my 2002 Grand Prix). in the morning, I noticed a very faint smell of raw fuel. closer inspection of EVERYTHING fuel related, no leaks at all. Gas
tank/sending unit are new last year, no wet spots or other obvious signs on the fuel lines, etc.
The smell is definitely under the hood...more explicitly, seems to be coming from the TBI unit. The smell seems to be coming from the cold air snorkel... the TBI unit is smelling a little bit. no obvious fuel leaks down the back of the FPR (tbi got a rebuild kit last year)...
whats the deal? anybody else have this? is something about to rupture?
b
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Ham...
You might want to check the 'charcoal canister' hoses
under hood or under front fender...
Hamilton Audio wrote:

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DONT LEAVE THE THING IN THE GARAGE UNTIL YOU FIX THE PROBLEM!!! It doesn't take much of a leak to make a strong gas smell in a closed area. Look for ANYPLACE that the fuel might come from...gaskets and seals on the TBI unit and the fuel lines.

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throttle body base gaskets often tear, i would look at that first. it's very easy to replace. It would be a good idea to clean the throttle plates when you replace the gasket.
If it's a torn gasket you would have an air leak that would most likely cause a high idle condition.
If not then maybe where the fuel lines go into the throttle body. Good luck

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well, its like this. a raw fuel leak is usually an easy one to spot on lines, cause its "wet". and the smell will lead you right to it (to my nose, raw gas is VERYpotent). also, if gas has been leaking around the tbi unit, crud usually develops as a result...and everything is sparkling clean. :) also, around the throttle body and such, the rebuild kit was done last year which replaced just about every gasket in there....so I don't /suspect/ it, but its possible. the truck doesn't idle high at all (if anything, a little too low due to aftermarket cam)
when I said the fuel smell developed in the garage, it was VERY faint (but noticeable to my nose) after an entire day...it took that long to buiild up, so the source is very faint. I've had buddies rides in the shop who had leaking gas tanks that left a lingering odor for days....based on that, I'd say the source is faint...

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Jason...E-mail me PLEASE!!! shades snipped-for-privacy@netins.net
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Oh just relax. Your gas cap probably needs to be replaced. The TB always smells like gas.
Doc

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Doc is SOOOO insightful :) :) Why did nobody else mention this? are you suggesting that the gas cap is NOT venting properly or something? :) All I know is when I smell raw fuel, I get panicky....
my wifes 2002 Grand Prix pulled into the shop smells like new car, and THATS it :)
b
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B,
Your fuel cap doesn't vent unless the internal tank pressure reaches critical levels, which for all intents and purposes is never. Your fuel vapors are <supposed> to be gathered by the charcoal cannister (located underhood) and then eaten by the motor as soon as the cannister purge solenoid opens. Gas caps age and fail to seal, allowing fuel vapor to escape thru the filler neck and not be stored in the cannister.
Another thing to look for is the evap line (runs from fuel tank sending unit to cannister) being rusted thru. Folks notice when a main or return line is faulty due to spilled gas everywhere, but a deteriorated evap line might go unnoticed for years.
Bottom line. TB always reeks of gas. Pull off the air cleaner lid and take a whiff. Gas caps cost $5. Evap lines are more trouble to replace than they're worth.
Doc

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good to hear doc. as far as your method for calculating fuel economy, I WILL DO EXACTLY AS YOU SUGGEST, right down to the decimal place starting with my next fillup...will then post back what I find after 2 cycles...
<rolls eyes> please don't flame me <rolls eyes again> :)
b

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. . . under-hood gas smell? Group: alt.autos.4x4.chevy-trucks Date: Sun, Oct 19, 2003, 1:55am (CDT+5) From: snipped-for-privacy@shaw.ca (HamiltonAudio) I parked my 91 Z71 in the garage last nite (usually occupied by my 2002 Grand Prix). in the morning, I noticed a very faint smell of raw fuel. closer inspection of EVERYTHING fuel related, no leaks at all. Gas tank/sending unit are new last year, no wet spots or other obvious signs on the fuel lines, etc. The smell is definitely under the hood...more explicitly, seems to be coming from the TBI unit. The smell seems to be coming from the cold air snorkel... the TBI unit is smelling a little bit. no obvious fuel leaks down the back of the FPR (tbi got a rebuild kit last year)... whats the deal? anybody else have this? is something about to rupture? b ========= =========
shove a piece of ass-wipe paper in the throttle body....under the injector....
see if it's wet the next morning.
marshmonster ~:~
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