
During its evolution, the fuel injector has moved from the
1. Turbo Troubles
In turbocharged engines, dirty injectors can have a dangerous leaning effect
2. Restrictions
A restriction of only 8% to 10%
Direct fuel injectors are more sensitive to restrictions
3. Increase or Decrease in Long- and Short-Term Fuel Trims
The fuel calibration curves
The PCM
• An injector becomes clogged with fuel varnish deposits and fails to deliver its normal dose of fuel when it’s energized, or
• Fuel pressure to the injector drops below specifications
This can leave the air/fuel mixture too lean, causing the cylinder to misfire.
4. Not Enough Resistance
The solenoid at
Typically, the solenoids often short internally when injectors fail, which causes a
5. Heat Soak
When the engine is shut off, the injectors undergo heat soak. Fuel residue evaporates
Since the formation
Heat soak can affect direct-injection injectors
6. Failed Balance Tests
If
A
Another effective test is
Ideally, each injector should drop
7. Misfire Codes
A lean misfire may trigger a misfire code
8. Longer Crank Times
An injector leak will cause the rail to lose pressure while the vehicle is sitting
A normal crank time
9. Lack of Maintenance
If an owner has neglected maintenance services like oil changes and filter replacements, the
10. Vehicle Won’t Start With Full Tank
Major symptoms of contaminated fuel can include cranking no-start, hard starting, stalling, loss of power, and poor fuel economy. Because symptoms of fuel contamination generally appear immediately after refueling, the