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Odd ball question, lol !

pearljam724

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With aftermarket 4-barrels, I realize you have to pump the pedal several times if the car has set a while to prime the carb throats. But, when your car has been running for a while. Let’s say you shut it off for 10 minutes at a stop. Do you guys have to hold the pedal to the floor to start it or simply turn the key ?
 
Most have fired right up....
That’s what I was figuring too. Then wonder why mine is fussy if I don’t hold it to the floor ? Everything is brand new except the fuel pump. But, that’s not causing it. Because I can verify fuel pressure with a gauge I have. I’m usually fairly good with anything carb related. I don’t understand it though. I think aftermarket cams throw a lot of normal tendencies or common diagnosis out the window. That or my gas is boiling causing it.
 
Holding to the floor is a way to start a flooded engine. After driving it, when you shut it off, pop the hood and look down the carb with a flashlight while holding the venturi open.
 
Do you guys have to hold the pedal to the floor to start it or simply turn the key ?

Many cars that i've had ( vintage ) the norm is pump it a few times if cold. One and only one pump if warm and it should fire right up, in my experience any way. If you have to hold it to the floor, it's gotten too much gas somehow.
 
what kind of carb is it?
deffo sounds like its leaking past the needle and seat/float if you have to clear it to restart.
use the flashlight and investigate like Greycharger said.
probably going to be one side of your discharge is leaking past the needle
because /dirt/corrosion etc etc.

do you have headers?
these put out a ton of heat into the engine compartment,and with todays shitty gas its easier to boil.
 
Edlebrock Thunderseries. No headers. I have an in-line filter. But, an old tank. The carb is only a couple years old. It probably is related to carb needing cleaned. I guarantee the gas boils. I can hear it sometimes if I listen closely. There’s nothing I can do to fix that. But, run a return line to my tank to help. I have no room under hood to add a thicker base plate. I know it’s not getting too much gas. Because of regulator, no smell of gas and I check plugs quite often.
 
The puppy pee gas we have now days will evaporate with a little heat. Edelbrock/Carter carbs are worse for it. The float bowls are quite small and they are bolted onto the engine soaking up the heat. Yes a fuel return filter will help as well as a spacer (which you can't use). Blocking off the heat riser passage will help as well. Some have mounted a small electric pump connected to a momentary switch to fill the float bowls after the fuel has evaporated out. There's no real good answer to fix the problem.
 
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My IH shop manuals say you should change the oil after a single flooding. Always sounded extreme to me, but oil was 50 cents per quart. The raw gas that gets past the rings will cook out, but it is supposed to hard on bearings.
So you do want to figure it out.

If you have room under the hood, you might be able to use a phenolic insulating spacer (1 inch thick on my Travelall 392). Some TQ's came with them to avoid boiling fuel problems.
 
The puppy pee gas we have now days will evaporate with a little heat. Edelbrock/Carter carbs are worse for it. The float bowls are quite small and they are bolted onto the engine soaking up the heat. Yes a fuel return filter will help as well as a spacer (which you can't use). Some have mounted a small electric pump connected to a momentary switch to fill the float bowls after the fuel has evaporated out. There's no real good answer to fix the problem.
Yeah I agree. But, as other guys stated. They are starting their cars with just a turn of the key. It wasn’t very warm here yesterday. About 80 and I still had to hold pedal to the floor.
I have a 1950 Chevy Deluxe. Those cars, the carb sits directly on top of the exhaust manifold. It has very bad vapor lock (gas boiling) issues. Single barrel carb. That car, you don’t dare shut it off if it’s over 70 degrees outside. Otherwise, it will never restart. Unless you give it at least an hour to cool off. Usually it takes longer. Today’s gas boils extremely easy. But, I think my problem is more carb related.
 
Yeah I agree. But, as other guys stated. They are starting their cars with just a turn of the key. It wasn’t very warm here yesterday. About 80 and I still had to hold pedal to the floor.
I have a 1950 Chevy Deluxe. Those cars, the carb sits directly on top of the exhaust manifold. It has very bad vapor lock (gas boiling) issues. Single barrel carb. That car, you don’t dare shut it off if it’s over 70 degrees outside. Otherwise, it will never restart. Unless you give it at least an hour to cool off. Usually it takes longer. Today’s gas boils extremely easy. But, I think my problem is more carb related.
It didn't act that way every day since 1950 though. May be an occasional vapor lock on a hot summer day after a hard drive. It's the fuel now days and some engine/carb combos are more susceptible. Dual float bowl Holleys aren't effected as much. The float bowls aren't directly over the intake and actually hang out over the edges in mid air. There is a cooling effect there. I bet Air Gap intakes are less effected. There again, another insulator. I bet you could put some good racing fuel in your old 50 Stovebolt and have no issues. Look at a old barn find that hasn't been run for decades. Chances it will run again on that old gas from the 70's. My 2 cars set for a few weeks and the carbs are dry. Bottom line, todays gas is the problem. Fuel injection is not effected much at all but 50 year old carb designs are. Set the choke light, block off the het riser, use a carb insulator, fashion a return system. They all help your issue.
 
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Welp guys. I completely cleaned the carbs today and did it thoroughly.,Blew out everything. Bowls were clean as a whistle before I started. Runs great, idled great. But, still have to hold pedal to floor to get it to fire. I don’t know ?
 
Welp guys. I completely cleaned the carbs today and did it thoroughly.,Blew out everything. Bowls were clean as a whistle before I started. Runs great, idled great. But, still have to hold pedal to floor to get it to fire. I don’t know ?

Holding the pedal to the floor, the car starts, now is it blowing black smoke then clears up?
 
Holding the pedal to the floor, the car starts, now is it blowing black smoke then clears up?
Exactly, a tad of black smoke was noticed for the first time today. Carburetor accelerator pump ?
 
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Exactly, a tad of black smoke was noticed for the first time today. Carburetor accelerator pump ?

Sounds like it's flooding over when hot. After you shut her down, when hot, the fuel can boil over and drip down into the manifold.

After a long run, take the air cleaner off and watch in the carb to verify.

It could be mostly from the heat soaking into the base of the carb doing this. A phenolic spacer can limit this.

The float level being a tad high will also contribute to fuel leaking into the carb when hot. Lowering or making sure the float level is correct to start with, will help.

Useing ethanol free gas can help if you have some in your area.
 
I tried non ethanol fuel once a few weeks ago. I have to drive about 35-40 miles to get it. It did the same thing. Float heights I didn’t check. Up until today, I thought I had zero room from a spacer under the hood. It turns out I actually have about 1/2 - 1 inch of room under hood. I’m positive a spacer would help and so would running a return line to the gas tank. But, I want to put that on hold until I decide to replace an old tank or not. Because the tank doesn’t leak. But, it may be an original. It’s that old. This carburetor doesn’t have an electric or manual choke. Therefore, It does the same thing when engine is cold. But, it always starts and won’t idle until it’s at operating temperature. Which is normal. My point is, it always has to be started with pedal to floor until it fires. My battery isn’t the greatest in that it labors to get it started. But, always does. Previous owner put some cheap remanufactured battery in it. I’m not going to replace battery as long as it’s doing it’s job. But, I wonder if it’s the problem having to hold pedal down ? Because the pump would pump less fuel due to a slower crank speed ? Why did you assume black smoke ? Because that happens when fuel boils over into manifold ? Thank you
 
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Why did you assume black smoke ? Because that happens when fuel boils over into manifold ?

Yep. It's all loaded up just like having the choke on too long. Plus you said the only way it will start is having your pedal on the floor. That's the only chance you have to get a flooded engine to start.

I've been useing 1/2" wooden spacers and they have been holding up ok. I'd shy away from plastic or aluminium. The composite ones supposedly work good but cost more.

Having the manifold cross over blocked off is sure to help. I used the manifold gasket with the port blocked.
 
Yep. It's all loaded up just like having the choke on too long. Plus you said the only way it will start is having your pedal on the floor. That's the only chance you have to get a flooded engine to start.

I've been useing 1/2" wooden spacers and they have been holding up ok. I'd shy away from plastic or aluminium. The composite ones supposedly work good but cost more.

Having the manifold cross over blocked off is sure to help. I used the manifold gasket with the port blocked.
Thank you for the help. So, you made your own spacer or one already manufactured by someone else made of wood ? Yeah aluminum is bad, conducts heat too well. My carb being aluminum is a larger problem than ethanol. Two combined is a bad recipe. Plastic just won’t last heating and cooling. I’d like to see some pics of what you did with the wood, spacers, etc.
 
Yep. It's all loaded up just like having the choke on too long. Plus you said the only way it will start is having your pedal on the floor. That's the only chance you have to get a flooded engine to start.

I've been useing 1/2" wooden spacers and they have been holding up ok. I'd shy away from plastic or aluminium. The composite ones supposedly work good but cost more.

Having the manifold cross over blocked off is sure to help. I used the manifold gasket with the port blocked.
Exactly.....
 
I’d like to see some pics of what you did with the wood, spacers, etc.

You can find the spacers on Summit or Jeggs. I used this one under my 600 Eldebrock

https://www.summitracing.com/parts/edl-8723

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