Mechanical Fuel Pumps: Troubleshooting

Insufficient fuel or no fuel delivery may not be due to a defective fuel pump, but the diagnosis could indicate a faulty fuel pump. Perform the following checks on the fuel supply system before testing, replacing or overhauling the pump.

1. Insufficient fuel supply.
2. Restricted fuel filter(s).
3. Leaks in fuel lines or fittings.
4. Dented, pinched or kinked fuel lines.
5. Collapsed flexible fuel hose.
6. Water and/or dirt in fuel supply.
7. Dirt or restriction in fuel tank.
8. Push rod worn.
9. Vent in tank restricted (will also cause collapsed tank).
10. Incorrect fuel pump installed.
11. Frozen or vapor locked fuel lines.
12. Defective fuel pump.