May 102016
 

Fuel InjectorThis car has 170,000 miles on it. One  injector seems to be stuck open. When power is cut to the fuel pump, it will run until the fuel line is drained.

Is it possible that the injector is bad, or is it more likely that it is stuck open as the result of another problem?


RESPONSE

I think you are right in your diagnosis. Fuel injectors do go bad and stick in the open position.

Identify the failed fuel injector.

  • Remove all spark plugs
  • Turn key to the on position- cycling the key may be required
  • Take note to which cylinder fills with fuel

READINESS MONITORS/DRIVE CYCLES

HO2S and Air Fuel Ratio (A/F) Sensor Monitor and Readiness
Monitor

NOTE: All readiness monitors are cleared when the battery is disconnected or when the
ECM/PCM is cleared with a scan tool.

Drive Cycle Procedure
1. Connect the scan tool.
2. Turn the ignition switch ON.
3. The MIL must be OFF.
4. The Engine Coolant Temperature (ECT) and the Intake Air Temperature (IAT)
should be greater than 41°F (5°C).
5. The Engine Coolant Temperature (ECT) and the Intake Air Temperature (IAT)
should be within 10 degrees of each other.
6. Do not turn the ignition switch off during the procedure.
7. Most OBD monitors will complete more readily using a steady driving style during
the acceleration and cruising modes. Operating the throttle in a smooth method
will help ensure and assist completing the monitors.
8. The fuel tank should be between ½ and ¾ full with ¾ full being the most desirable
level.
9. Start and idle the engine for five (5) minutes with the A/C and rear defroster ON.
10. Turn the A/C and rear defroster OFF and idle the engine until the Engine Coolant
Temperature (ECT) sensor reaches a minimum of 170°F (76° C).
11. Begin driving and accelerate the vehicle until the vehicle speed is 56 mph (90
km/h).
12. Release the accelerator pedal and keep it released for 10 seconds or more.
13. Accelerate again until the vehicle speed is at 56 mph (90 km/h) and continue
driving the vehicle at 53 – 60 mph (86 – 96 km/h) for 10 minutes.
14. Check the monitor for “COMPLETE” status. If the monitor status is not
“COMPLETE”, go to the next step.
15. Decrease vehicle speed to 0 mph (0 km/h).
16. Let the vehicle idle at 0 mph (0 km/h) 60 seconds.
17. Accelerate to 30 – 35 mph (50 to 55 km/h).
18. Drive the vehicle between 30 – 35 mph (50 – 55 km/h) for 5 minutes.
19. Decelerate to 0 mph (0 km/h).
20. Let the vehicle idle at 0 mph (0 km/h) for 45 seconds.
21. Drive the vehicle at 53 – 60 mph (86 – 96 km/h) for 5 minutes, holding the
accelerator pedal very steady. Monitor the Throttle Position Sensor (TPS)
voltage; it should be between 0.8V and 1.2V.
22. Decelerate (coast down) to a stop without braking.
23. Let the vehicle idle at 0 mph (0 km/h) for 45 seconds.
24. If the readiness monitor is still set to incomplete, check for a temporary DTC. If
there is no DTC, one or more of the enable criteria were probably not met; repeat
the procedure.
25. Allow the vehicle to sit (key OFF) for 8 hours and repeat the procedure.

 

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