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Don't know where to begin. My '71 454 had a complete rebuild, all stock. Entire fuel system replaced including rebuilt Q-Jet. Only mods are Flamethrower distributor and headers. After a few hundred hundred miles of trouble free driving, and only on occasion, when driving at 40mph+ after moderate acceleration, it will stall. Pull over, starts after sitting 5-10 minutes then seems fine. 70 degree ambient. Fuel filter clear. Haven't torn onto carb yet. Fuel pump seems ok. Thoughts?
 

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Don't know where to begin. My '71 454 had a complete rebuild, all stock. Entire fuel system replaced including rebuilt Q-Jet. Only mods are Flamethrower distributor and headers. After a few hundred hundred miles of trouble free driving, and only on occasion, when driving at 40mph+ after moderate acceleration, it will stall. Pull over, starts after sitting 5-10 minutes then seems fine. 70 degree ambient. Fuel filter clear ? Haven't torn onto carb yet. Fuel pump seems ok. Thoughts?
So when it stalls out do you have gas in the fuel filter or is it empty ? Do you have a vacumm gauge ? You can check fuel pump pressure with one if you do.
 

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Is that an HEI type distributor? If so, replace the module in the distributor and see if it helps anything
 
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The Qjet wont like fuel pressure much over 6 psi. I'm thinking the moderate acceleration builds psi to the point where it stalls it by overwhelming the needle/seat and overfilling the relatively small bowl on a Qjet. If you popped the air cleaner off during an "episode", the carb ought wreek of fuel. Also if this is the case, check engine oil for excess unevaporated fuel.

Or, as above, it could be an ignition component going away, which modules do when warm.
 

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The Qjet wont like fuel pressure much over 6 psi. I'm thinking the moderate acceleration builds psi to the point where it stalls it by overwhelming the needle/seat and overfilling the relatively small bowl on a Qjet. If you popped the air cleaner off during an "episode", the carb ought wreek of fuel. Also if this is the case, check engine oil for excess unevaporated fuel.

Or, as above, it could be an ignition component going away, which modules do when warm.
I know that Sean Murphy recommends ~4-5 psi for his Stage 2 QJets.

Corey
 

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If this only happens after 'moderate acceleration', I think it is unlikely to be spark related.

More likely fuel related. Fuel pump good? Make sure the fuel tank venting system is working properly.

Does it stall when actually accelerating, or when you lift off afterwards?
 

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Make sure the fuel tank venting system is working properly.
THIS ^ ^ ^ ^ ^ ^

Remove your fuel filler cap and see if it stalls.
 
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