<VV> Fuel issues! Smoking Gun?

[djtcz at comcast.net]

----- Original Message ----- 
-----Original Message----- 
From: kenharri at comcast.net 
Subject: <VV> Fuel issues! Smoking Gun? 

Hello, I have been having issues with my FC.? She runs well most of the time but has always (in the year I have had her on the road) stumbled under hard acceleration. Lately she just does not want to do more than a couple thousand RPM.? Yesterday it turned into a few hundred RPM, then nothing.? All the usual tricks would not work.? The best I could get her to do is run at 2000 RPM for 15 seconds then quit.? I hooked up a clean 2 gallon fuel source to the fuel pump input?line, no change. I replaced the carbs with a known good pair, no change.? I replaced the fuel pump and also had no change.? Towed her home.? 



I opened up the carbs and found them pretty clean with no?noticable defects.? I opened up the 1 year old fuel pump and found both valves installed with?the same orientation (see attached photos) with the inlet valve cocked off to one side.? I am no fuel pump expert but shouldn't they have an? opposing orientation to each other to suck through the inlet side then push through the outlet side ? 

You fuel system experts out there, where are you? 
Thanks for your input! 

Kent Harrington 



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When you took the carbs tops off was there fuel in the bowls? 


I do a series of tests before exchanging parts. 
1 - watch for fuel squirting into the throat while stroking the carb linkage. The accelerator pumps should deliver a squirt on each (primary) carb. 
2 - If no fuel squirted I'd check (test) the fuel pump pressure and delivery volume. A line from the pump discharge side should deliver generous squirts of fuel into a clean coffee can etc when the engine is cranked. Fuel pressure should be 4-5 pounds or somesuch. Testing after the filter is better since it would reveal a functionally clogged filter. I would not change a filter that allows fuel to pass freely. 


The 1965 shop manual includes fuel pump spec of 1 pint in 30-45 seconds. That fuel flow would support at least 120 real HP. 


Dan T