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Carb. issue....need help.

70 StangMan

70 StangMan

Well-Known Member
Donator
Alright...I put on a rebuilt Autolite 2100 carb. a few months ago. What I'm finding out now is that in order to get the engine to fire and run (after sitting a few days) , a small amount of gas MUST be poured into the top of the carb. or the engine will just turn over and over (forever) without firing. Once said gas is dumped in it will run fine and start over and over. There is gas in the bowl prior to attempt to start (about a 1/2" below the top) and is full after the engine turns over a few times but not fired. Any ideas ????
 
Hmmm, fuel pump should fill the bowls. Over the winter, I drain the Holley carb and when I go to restart in the spring, I fill up the bowls through the vent tube and it fires right up. As long as I don't drain the carb, it always fires off even after sitting for a month.

Do you have an electric or mechanical fuel pump?
 
Have you check the fuel pressure? Disconnect fuel line and crank it over into a jug if you don't have a gauge.




edit - nevermind, I went back and re-read your post.
 
Pumping the gas pedal should shoot fuel down the carb. Remove the air cleaner and watch down the carb as you manually pump the throttle linkage. Does it shoot gas? If so, then pumping several times will be nthe same as pouring a small amount in the carb,

Sounds to me like you have a vac. leak. Takes an exceptional amount of gas to counter act the excessive air flow form a leak.......
 
"AzPete" said:
Pumping the gas pedal should shoot fuel down the carb. Remove the air cleaner and watch down the carb as you manually pump the throttle linkage. Does it shoot gas? If so, then pumping several times will be nthe same as pouring a small amount in the carb,

Sounds to me like you have a vac. leak. Takes an exceptional amount of gas to counter act the excessive air flow form a leak.......
Click to expand...
Just checked...Yes, when pumping the throttle linkage it does squirt gas into the carb. Could it be the choke is set to far closed ?? Just thinking out loud.
 
The choke will open enough to allow starting.

If you attempt to start it and pump the pedal numerous times(I mean a whole bunch while cranking the starter), does it start? Still sounds like it is taking more gas to start....because there is to much air. How much black smoke from the tail pipes once it starts?
 
You don't need a choke in Florida! My carb doesn't have a choke.
 
"AzPete" said:
The choke will open enough to allow starting.

If you attempt to start it and pump the pedal numerous times(I mean a whole bunch while cranking the starter), does it start? Still sounds like it is taking more gas to start....because there is to much air. How much black smoke from the tail pipes once it starts?
Click to expand...
Tried pumping like I was getting paid for it, I tried holding the pedal all the way to the floor, I tried not pumping at all (all on different occasions) trying to find the magic formula...but the results are always the same. Nada unless fuel is added to the carb.
 
"AzPete" said:
Convert to a 4100.....

Has the car backfired at all......power valve could be bad.
Click to expand...
I really need to make this one work...$ wise. I want a aluminum intake w/4 barrel but that will have to wait till the money situation gets better.
 
I couldn't tell what all the PO had done to make it still run. Leaked at the acc. pump. ( gas would puddle up on the intake) Broken fresh air inlet for the choke. Sh*t wired up here and there. I found a very good deal on a re-man. so I decided to start fresh and eliminate all the problems (so I thought)
 
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