The Stovebolt Site Forums The Shop Area Engine Shop Fuel starvation

My 1960 235 started running rough ... no power to even move 10 feet. Noticed the inline filter had relatively little fuel so I pulled the fuel pump (only about a year old) and operated it by hand ... pumped fine and refilled the filter as normal.. so now I don't think it's the pump.

Any ideas what to look for?

Many Thanks!

That is not a good test for a pump. You must be pretty powerful to operate that pump. The test for pumps is to run output into a container during crank to see volume while pump is installed on motor. (dizzy primary lead removed) Some aftermarket inline glass and non glass filters don't stay full but fuel in carb will start motor and fuel will flow if all is well. Take the filter out of the system with a piece if tubing clamped in it's place and check improvement. If flow from pump is good and taking out filter does no good= carb needle valve/dirt, air leak on suction side or clog in line/tank or not a fuel issue at all.. Get an all metal, sealed can filter.
Is your filter before or after pump?

Thanks Bartamos... good suggestions ... will try them all. Filter is before pump. I too was surprised I could pump the fuel by hand... while a bit stiff if I pushed out on the end with max leverage it worked.. and pushed a large flow.. while my suspicion was the fuel pump ... I do have my doubts since its virtually new ....
smell if gas and coffee first thing in the morning does a man good!

The standard test of a mechanical pump is 1 pint of fuel pumped into a catch can in 30 seconds at idle speed. If the engine won't idle for half a minute from the fuel in the float bowl, you've got other problems. If the pump fails the volume test, you're not done- - - -check for 3-5 PSI of output pressure with at least a few seconds of pressure on the line after shutdown, and 10-15 inches of vacuum on the suction side, also with a few seconds of vacuum held after the engine stops. If the pump passes both pressure and vacuum tests, find the restriction in the line from the pump to the tank, a clogged tank pickup line, or look for an air leak somewhere. The flex line from the frame to the pump can suck air without leaking gas.
Jerry
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Let us know what you find, it helps for future.

Thanks guys... may take a bit to get back to it .... but I will post the results.