Here are 10 signs to look for when you need to replace a fuel injector or it needs service:
1. Restrictions
A restriction of only 8% to 10% in a single fuel injector can lean out the fuel mixture and cause a misfire.
2. Turbo Troubles
In turbocharged engines, dirty injectors can have a dangerous leaning effect that may lead to engine-damaging detonation.
3. Heat Soak
When the engine is shut off, the injectors undergo heat soak. Because the engine is off, there is no cooling airflow moving through the ports and no fuel flowing through the injectors to wash it away.
4. Increase or Decrease in Long- and Short-Term Fuel Trims Fuel pressure to the injector drops below specifications because of a weak fuel pump, plugged fuel filter or leaky fuel pressure regulator. This can leave the air/fuel mixture too lean, causing the cylinder to misfire.
5. Not Enough Resistance
The magnetic field must be strong enough to overcome the spring pressure and fuel pressure above the pintle, otherwise the injector may not open all the way