Thread: Carb Jets
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Old 06-14-2025, 07:47 PM   #18
TomC750
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Location: Eastern Tennessee
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Default Re: Carb Jets

Quote:
Originally Posted by ford38v8 View Post
OK, I got it... your fuel pump is not delivering. The problem can be the pump itself, an air leak before the pump, a restricted fuel line before the pump, or a non-vented fuel tank. Surging is the key word in your problem. I take you at your word that your carb has been correctly rebuilt and float adjusted properly. Your choke pulled out slightly helps pull the fuel through the pump.

You should have from 1 to 4 lbs pump pressure.
An air leak or a restriction will reduce volume and pressure. Do you have a glass bowl pump? An air leak may show bubbles there. Use cork gaskets there, soaked in oil. Check connections and hose clamps. Wire spring hose clamps are no good, replace with worm gear clamps. Fuel lines can deteriorate and develop pinhole air leaks. A fuel line leak before the pump will never leak gas, but will suck air.

A restriction can be dirt in the fuel lines, a fuel filter needs replacing, or an internally collapsed flex line. These are reproduced fuel resistant, advertised in the V8 Times under Shewman. Do not get the check valve type.

Non vented tank requires a vented cap. Have you replaced fuel caps lately without regard to venting?
I will admit I have not checked fuel pressure. I should do that, but have not bothered since it pulls strong and reaches for the stars at full throttle. Otherwise I have covered all the bases you mentioned. The car has an electric pump as well as the original. I only use the electric one to prime It has no effect on the running otherwise.
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