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Discussion Starter #1
I installed a sbc in my 59 chevy truck and I have a problem with fuel delivery after the truck sits for a couple of days. When the truck sits for a couple of days the fuel drains back towards the mechanical fuel pump(Jegs) and I have to crank the heck out of the motor to get the fuel back up the fuel line and into the edelbrock(carter) carb so the engine will fire. I now that the fuel is moving back because I have a clear glass fuel filter installed and the bowl is dry prior to cranking the motor over. Any thoughts on what the problem is or tests I can do to isulate the problem would be helpful.


John
 

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jw4413nv said:
I installed a sbc in my 59 chevy truck and I have a problem with fuel delivery after the truck sits for a couple of days. When the truck sits for a couple of days the fuel drains back towards the mechanical fuel pump(Jegs) and I have to crank the heck out of the motor to get the fuel back up the fuel line and into the edelbrock(carter) carb so the engine will fire. I now that the fuel is moving back because I have a clear glass fuel filter installed and the bowl is dry prior to cranking the motor over. Any thoughts on what the problem is or tests I can do to isulate the problem would be helpful.


John
There should be enough gas in the carb to run engine till pump picks up the gas even if its been sitting awhile.
 

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That was a common problem on Quadrajets. If someone removed the stock fuel filter that was in the carb housing, the gas would syphon back. The stock filter had a one way valve built in. Does the Carter have a similar built in filter, that was removed when the inline filter was put in. You need a one way valve in the filter.
 

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I was going to mention the check valve filter too... I had a '76 Chevy that developed this problem after a garage used the wrong type filter in the carb.
 

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The problem with Quardajets was not drain back (or that may have been another problem), it was internal leakage from the float bowl into the intake manifold. When you remove a Quadrajet body from it's base plate you see two lead plugs. These plugs leaked and would allow the float bowl to drain into the intake manifold. A fix GM came out with was a kit that contained some epoxy and a form fitting foam plug that set down into the well and was compressed by mounting the float bowl to the base plate. Later Quadrajets did not have this problem and it seemed to be limited to 60's and early to mid 70's cars.

Vince
 

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The Edelbrock/Carter carb is an AFB, NOT a Quadrajet. The AFB has 4 equal size butterflies, the Q-jet has tiny primaries and MONSTER secondaries.
 

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1967 Chevrolet Biscayne 10-71 blown 433 Big Block Chevy, T400 & 12 bolt 3.73 rearend
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The needle and seat assembly only control the incoming fuel. Once the fuel is on the bowl, it has no impact on it.
 

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Discussion Starter #9
problem solved

I installed an inline filter with a drain back check valve and the problem is solved. Thanks for all the advise.

John
 
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