392 w/Holley 4bbl Intermitant sputter shortly after pulling hill

W

waveraider

New member
I have an 1890 loadstar that I thought had a fuel delivery issue. Anytime I pull a hill or really put it under a load it will cough and sputter but not right away. Normally I can just downshift and make it through. Its only had about 1500 miles since I put a new fuel pump on but that was 4 years ago. The inline filter was awful so I changed that and flushed out the fuel tank. Seemed to do a bit better but ultimately not too much difference. I plugged the fuel line into a gauge and it was 5psi but then increased to about 8 over time after the motor was shut off. I assume it was the fuel line warming up the cold fuel- about 10 min. I never did wait long enough to see if it would die back down. I'm wondering if I should check under dist cap to see if timing advance is ok. Any help is appreciated
 
Small screen at carburetor is and has been clean. I even took the aft bowl off because at one point fuel was trickling up out of the bowl vent tube. The bowl was all clean and float operation good. I would plug the vent tube of with my finger and then it would run fine. I plugged it off with a pencil and drove home. It has never done that again but still does the same sputter thing
 
Well then at the other end of the system is there May be a filter on the end of the dip tube in the fuel tank. It just doesn't sound like an ignition problem to me, but to be sure you could wire a multi-meter from the cab to the coil + and see how the voltage holds up under load. With a stock points ignition you should measure around 9v at the coil while running.
 
I have replaced the points with the newer electronic points system. I don't recall brand it is though. I don't think there could be a dirty filter in the tank. I spent about 30 flushing it out with a pressure washer till the water was clean and free of all debris. Thank you for your help
 
It would be easy enough to disconnect the fuel line at the carb and put it in a can while cranking the engine to see if you've got a good flow of fuel to the carb.
 
I just reciently had to replace the fuel pump on my 345. At idle and low rpms it ran fine, but at about 2000 rpms and up it would act like it was running out of gas. I have one of those glass fuel filters before the pump (yes I have a canister filter also). At idle the glass filter was full of gas, if a reved up the motor it would suck it dry and almost no fuel was traveling through it.
Replaced the pump, no more problems.
 
I've got a new fuel pump and was about to put it on but wondered if there was a higher flow model than the standard stock one.
 
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