Carburetor help needed, Please !
Thread Starter
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Joined: Aug 1999
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From: SE Pennsylvania
St. Jude Donor '03 thru '26
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Carburetor help needed, Please !
I was wondering if someone can hepl me diagnose a carb problem I think I have, If I go to start the Vette after it has been sitting unstarted for about two weeks, it acts flooded and starts hard? Does this mean the carb is getting weak. It was rebuilt about six years ago. Any help appreciated.
Melting Slicks
Joined: Sep 2000
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From: Chester Virginia
Re: Carburetor help needed, Please ! (killain)
Please define "starts hard" and "the carb is getting weak".
If the car has sat for two weeks the gasoline will have evaporated from the fuel bowl. The only way to get fuel into the engine is to first fill the fuel bowl and then the engine will 'pull' the gasoline from the carburetor into itself or 'pump the accelerator to add the gasoline. When you start the engine it will take several engine turnovers to replenish the gasoline into the fuel bowl. Then you can 'pump' the accelerator to put gasoline into the intake for starting - like you would for normal start-up procedure. If enough gasoline has evaporated over time fuel additives can be left in the ports in the carburetor restricting the normal fuel flow. This condition will usually be detected by poor performance at idle and acceleration.
Roger
If the car has sat for two weeks the gasoline will have evaporated from the fuel bowl. The only way to get fuel into the engine is to first fill the fuel bowl and then the engine will 'pull' the gasoline from the carburetor into itself or 'pump the accelerator to add the gasoline. When you start the engine it will take several engine turnovers to replenish the gasoline into the fuel bowl. Then you can 'pump' the accelerator to put gasoline into the intake for starting - like you would for normal start-up procedure. If enough gasoline has evaporated over time fuel additives can be left in the ports in the carburetor restricting the normal fuel flow. This condition will usually be detected by poor performance at idle and acceleration.
Roger
Thread Starter
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From: SE Pennsylvania
St. Jude Donor '03 thru '26
Oldtimer
Re: Carburetor help needed, Please ! (RMS73)
Even after sitting for two weeks and not been started, the engin floods very easily. I was wondering if the carb isn't leaking fuel down into the engine after I shut it off? Why else would it flood so easily? :confused:
Thread Starter
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From: SE Pennsylvania
St. Jude Donor '03 thru '26
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Re: Carburetor help needed, Please ! (Vetterodder)
I first turn the engine over for a few seconds, then hit the gas once and then turn the key again?
Melting Slicks
Joined: Sep 2000
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From: Chester Virginia
Re: Carburetor help needed, Please ! (killain)
Turning the engine over a few turns should fill the float bowl with gas. Pumping the pedal once should not flood the engine. If the engine is flood, strong gas smell, then you may have a gas leak inside the carb. The pressed in caps on the bottom of the carb for the primary and secondary passages have a history of leaking. This leak is from the bottom of the carb bowl directly into the intake. When I was rebuilding my carb I cleaned the caps and surrounding area and epoxied over the surfaces. This is a common practice for Quadrajets.
Roger
Roger
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From: Maryland
Re: Carburetor help needed, Please ! (ridged84)
Killain, when I start my car after a long period I pump the gas pedal 4 times before turning the engine over. If it doesn't start then, I'll pump once or twice more and then turn it over. It sounds like there might be some sort of other issue going on with regards to the flooding. FWIW, the plugs on my Q-jet have not been epoxied. ~Juliet
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From: CORVETTE 77 385 C.I. TEXAS
Re: Carburetor help needed, Please ! (Juliet)
You should not be turning over first, nor do you want to set the choke in hot weather. In cold weather 1 pump to the floor sets the choke. In hot weather this can cause a problem & can be fixed by holding choke open to start.
Normally give a little gas & should fire right up. Engine hot, just turn over & should fire right up.
Sounds like there is a possibility both you & Juliet have something wrong like the choke adj.. Choke may be too tight on yours & too loose on Juliet's Vette.
Juliet
Can be started quickly w/o a choke in cold weather by pumping while cranking.
Normally give a little gas & should fire right up. Engine hot, just turn over & should fire right up.
Sounds like there is a possibility both you & Juliet have something wrong like the choke adj.. Choke may be too tight on yours & too loose on Juliet's Vette.
Juliet
Can be started quickly w/o a choke in cold weather by pumping while cranking.
Thread Starter
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From: SE Pennsylvania
St. Jude Donor '03 thru '26
Oldtimer
Re: Carburetor help needed, Please ! (Ganey)
I have a feeling there is some leaking going on inside the carb, I turn the engine over a few times to bring the oil up into the heads and then I hit the gas once. It is a problem that has been coming on for the last few years on and off. :confused:
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From: Kewaunee Wi
Re: Carburetor help needed, Please ! (killain)
You must touch the pedal first to reset the choke, other wise it stays wide open from the last time you ran the engine, also try pumping the accelerater at the carb to see if it is pumping any gas at all . might need a new accelerator pump in carb.
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From: CORVETTE 77 385 C.I. TEXAS
Re: Carburetor help needed, Please ! (killain)
If you are saying it will start fine after a week, but not 2 weeks, then any leak is very small & it would not be flooded from that.
Check accel. pump shot, then after sitting so you can see any difference.
Juliet, you too.
Check accel. pump shot, then after sitting so you can see any difference.
Juliet, you too.
