Fuel Pump Problems

Today marked the installation of the second fuel pump.  I thought the first fuel pump was bad since it quickly stopped pumping fuel.  Enough to fill the lines to the pump but sent no fuel to the carburetor.  The pump’s lever arm could be depressed a slight amount which was enough to produce noticeable suction.  After turning the motor over for a few revolutions with the pump installed, no more suction.  It appears that the pump is being damaged.  The fuel lines were then disconnected and the inlet tube was placed directly into a bottle of fuel.  Curiously, the inlet tube pushes air into the bottle of fuel every revolution instead of sucking.  When the pump was removed and operated by hand, no more suction like before.  The two pumps were for a Pontiac 301 motor.  This pump was chosen for the correct direction of the fuel inlet tube.  I stopped by CLC Machine Shop in Lynchburg to pick up a pump for a ’73 400 motor.  I’ll try this pump to eliminate any possibility that there may be a difference between the two pumps.  If anyone has any ideas, please feel free to leave a comment.

**Update, 3/27/2010** CLC supplied a fuel pump for a ’73 Bonneville which had the fuel inlets pointing to the driver’s side which is correct for the ’81 Trans Am.  It is still unclear whether the fuel pump for the 81 was the problem or it was actually two bad pumps.  At any rate the pump for the Bonneville works fine.


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