Fuel Pump Relay

Always inspect your fuel pump relay when replacing the fuel pump. A worn or damaged relay can cause low voltage.

Diagnosing A Fuel Pump

When diagnosing a fuel pump make sure to check the voltage & ground connections at the fuel pump. When checking with a voltmeter the voltage should be within 0.5 volts of the battery voltage.

Fuel Vapors

Fuel vapors are more flammable than the liquid fuel. When working with injectors, fuel filters, fuel pumps, and the fuel tank, be sure someone doesn’t walk by with a lit cigarette. Sparks created from metal hitting metal could also light fuel vapors. Though it is rare, static electricity enough of it could light fuel vapors. Though it sounds silly, always remind people around you that there are fuel vapors if you are working with an open fuel tank. If you have to repair a fuel tank, do not assume that the vapors will evaporate after a day with the tank open. It is never safe to weld a fuel tank without properly cleaning it.

Don’t Ignore The “Big 5” Noises!

Strange sounds usually indicate a problem, but these “Big 5” noises indicate urgent issues that should be addressed immediately to prevent further damage such as having a wheel fall off while driving:

  • Cyclic squealing or chirping from a wheel = bad wheel bearing
  • Metallic grinding or scraping during braking = brake pads completely worn out
  • Hissing from the engine during or after driving = leaking coolant or overheating
  • Tapping or clicking from engine = oil pressure too low
  • A roar from the exhaust while driving = faulty exhaust system; deadly carbon monoxide leak possible