My car has been vapor locking when the outside temp. is higher than 90 degrees. What is causing this? Could it be the heat from the exhaust heating up the tank and not enough cool air? The car stays under 190 degrees. Also wondering what the fuel charcoal canister does.

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1992 Camaro Z-28 5.7L auto t-tops arctic white

1967 Pontiac Catalina 2 door fastback 400 v-8 auto cameo white dark red interior

 

Pretty difficult for an EFI F-Body to vapor lock, due to the constant return/bypass of the fuel to the tank.

Basically the Charcoal Cannister takes the fumes from the tank, and vents them to the TB under certain conditions.

What exactly is the car doing that leads you to belive it's vapor locking?

 

Right... TPI cars have 40 psi in the fuel line, more or less... vapor lock is completely non-existent... what are the symptoms that you think are vapor lock?

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"So many Mustangs, so little time..."
ICON Motorsports

 

The gas tank starts making a moaning sound, and the next thing i know my car is running like the fuel filter is clogged, then it dies. I have to remove the gas cap and relieve the pressure and let it sit for a couple minutes. Then its fine again. But should it take over a minute to relieve all the pressure? Is the charcoal canister doing its job? Or is the fuel pump weak? Thanks for any help.

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1992 Camaro Z-28 5.7L auto t-tops arctic white

1967 Pontiac Catalina 2 door fastback 400 v-8 auto cameo white dark red interior

 

The gas tank is supposed to have pressure in it. In alot of modern cars, the ECM will set a code if the pressure doesn't build up. Besides, the 1 or 2 psi in the tank is insignificant compared to what the fuel pump is doing.

Your suggestion of a weak fuel pump might be a possibility, although I can't see how relieving the pressure in the tank would have anything to do with that.

Any possibility that the "moaning" sound is the fuel pump?

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"So many Mustangs, so little time..."
ICON Motorsports

 

Is the air going into or comming out of the gas tank when you remove the cap? It sounds like you have a blockage in the supply or the return line.

Bear Tracks

 

The pressure is coming out. And sometimes it will shoot gas out down the side of my car. There is alot of pressure. Dont want it to blow on me.

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1992 Camaro Z-28 5.7L auto t-tops arctic white

1967 Pontiac Catalina 2 door fastback 400 v-8 auto cameo white dark red interior

 

P.S. when I get under half a tank I keep the cap loose a little bit. Then It doesn't do it. It usually doesn't do it when its over half full.

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1992 Camaro Z-28 5.7L auto t-tops arctic white

1967 Pontiac Catalina 2 door fastback 400 v-8 auto cameo white dark red interior

 

This may sound stpid, bt what exactly is Vapor Lock, and what does it do?
Later
Mike

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(Gran Turismo Americano) "The Ultimate Firebird"
Smokin 1989 GTA- Bone stock except for exhaust. (no catalytic-stainless pipe into Flowmaster 2 chamber).

 

LOLOLOOLOLOL. for those of you who watch simpsons, "im troy Mecure, and now its time to talk about a real problem....... Vapor lock."
lol.
sorry,
yea im seconding this comment, i have a 305v8TBI.
and what happens is:
high pressure, never had it shoot at me, just goes, weeeeeesshh..... then at times i will have my foot at a certain point on the pedal and the car will chug, and you can slam the gas and shell accel reallllly harsh, and struggle. and then when i turn on AC it happens easier.
this problem sux guys. we need to fix this.

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91 FireBird 305 V-8
Edelbrock Catback, Fourth Gen Console. i have six cupholders. all for starbucks!
ghetto rigged cold air intake,
GheTTo Riggers INC.
We Make Mcgyver look Like Crap
God Created The Earth, And Then Turned Up The Bass

Part Search, I NEED A Harness For A Radiator fan, THANX

 

Oh it sucks, thats for sure. Scared to drive around town on hot days. And it sucks to have to keep the tank practically full.

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1992 Camaro Z-28 5.7L auto t-tops arctic white

1967 Pontiac Catalina 2 door fastback 400 v-8 auto cameo white dark red interior