A 40 micron element it sufficient to protect the pump from contamination such as dirt rust fuel cell foam etc. Electric pumps need a clean and stable power source.
How A Fuel Pump Works
New electric fuel pump not pumping. Blown fuel pump relay relay is energized by pcm to route power to fuel pump when ignition is on. If the fuel pump is electric the 12 volt power may be shorted. A hole in the fuel line on the tank side could also cause the fuel pump to suck air instead of fuel from the fuel tank. This is one of the more common fuel pump problems found in classic cars that are between 30 and 60 years old. Make sure that a low restriction filter is between the tank and the pump. Mallory has them available that will screw directly into the pump itself.
If the electric fuel pump is not working and it is not feeding fuel like its supposed to the gdi pump wont be able to do its job either. When the internal diaphragm leaks fuel escapes through the weep hole to notify the vehicle owner of a malfunction. Bad fuel pump pump should run for a few seconds when ignition key is turned to start no buzz means no fuel delivery to the engine. Sitting for 10 months while waiting for the new gas tank may have caused a problem im not aware of though. We call this a pulse the power created by the pulse is transmitted through a vacuum line from the lower end of the engine through the fuel pump or pumps. The fuel pump has several nozzles on it fuel in accepts the gasoline while fuel out sends it out the other side.
Most mechanical fuel pumps have a weep hole on the bottom of the unit. The only thing i can think of that could cause it not to pump is an obstruction upstream somewhere. There may not even be signs of leaking since a fuel line leak on the tank side would have to be above the fuel level for leakage to show. If for some reason no code is recorded make sure the problem doesnt come from the conventional fuel pump in the tank. While the pistons move up and down the crankcase pressure will vary. I dont think this is the problem since it worked fine before.
Gallery of New Electric Fuel Pump Not Pumping
