jtmx29
New Member
- Joined
- June 5, 2023
- Messages
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- City, State
- CT
- Year, Model & Trim Level
- 2008 Explorer Sport Trac
Hello All,
My Uncle owns a 2008 Ford Explorer Sport Trac with a V8 4.6L 3V engine. The vehicle has only 60k and has run very well for the past two years since he purchased it. Unfortunately, last week the vehicle took a turn for the worse. My cousin, who was driving the vehicle, said it suddenly started running poorly.
The main complaint is a rough idle and low power, although, the vehicle can be driven. My Uncle has taken it to a Ford dealership as well as two other mechanics and no one can tell him how to fix the problem. The Ford dealership mentioned replacing the entire wiring harness but that this would be no guarantee. The other shops mentioned a valve adjust or some type of 'drive train' issue. From what I understand is that between all 3 shops a compression test and smoke test were completed. Compression was fine and no vacuum leaks were detected.
My uncle has cleaned the MAF sensor, replaced all O2 sensors, replaced the cam shaft sensor, and replaced all 8 spark plugs-- the issue has persisted.
I went over there tonight to use my bluetooth OBD2 scanner to grab the codes. I am not a mechanic but enjoy learning about vehicles and how they work. First off, the vehicle runs rough at idle and under RPM load. It honestly doesn't run terrible, but it doesn't run great either. I hooked up my scanner and connected it to my Android tablet. Here were my findings:
P0174- Powertrain
System too Lean (Bank2)
P0208- Powertrain
Injector Circuit - Cylinder 8
P0301- Powertrain
Cylinder 1 Misfire Detected
P0352- Powertrain
Ignition Coil ‘B’ Primary/Secondary Circuit
I cleared the codes and re-scanned after the car had been idling for 5 minutes:
P0208- Powertrain
Injector Circuit- Cylinder 8
P0301- Powertrain
Cylinder 1 Misfire Detected
Raw Data:
Fuel Rail Pressure: 38 PSI
Mass Airflow Sensor Rate: 5.31 g/s
02 Sensor 1: .72 Volts
02 Sensor 2: .78 Volts
02 Sensor 5: .11 Volts
02 Sensor 6: .12 Volts
Fuel Trim Bank 1 Short: -8.59%
Fuel Trim Bank 1 Long: -4.69%
Fuel Trim Bank 2 Short: 21.09%
Fuel Trim Bank 2 Long: 25%
Now, based upon what I have learned is that the 02 sensors should 'loop' from low voltage state to a higher voltage state. Two of the sensors stayed at .1-.12 Volts while the other two stayed around .75 Volts.
Additionally, the fuel trim for banks 1 and 2 appear to fluctuate a bit, but the values above are after the vehicle had been warmed up and running for 5-10 minutes. Based upon the values for Bank 1 I would say it's running a bit rich while Bank 2 is running extremely lean. We upped the RPMs and bank 2's fuel trim did not get any better, so the mechanic who said there were no vacuum leaks may have been correct.
So, after all is said I am not sure what to recommend that my Uncle check next. I was thinking of maybe checking the resistance on the 8th cylinder's fuel injector.
Does anyone have any recommendations? I am truly stumped. Thank you!
My Uncle owns a 2008 Ford Explorer Sport Trac with a V8 4.6L 3V engine. The vehicle has only 60k and has run very well for the past two years since he purchased it. Unfortunately, last week the vehicle took a turn for the worse. My cousin, who was driving the vehicle, said it suddenly started running poorly.
The main complaint is a rough idle and low power, although, the vehicle can be driven. My Uncle has taken it to a Ford dealership as well as two other mechanics and no one can tell him how to fix the problem. The Ford dealership mentioned replacing the entire wiring harness but that this would be no guarantee. The other shops mentioned a valve adjust or some type of 'drive train' issue. From what I understand is that between all 3 shops a compression test and smoke test were completed. Compression was fine and no vacuum leaks were detected.
My uncle has cleaned the MAF sensor, replaced all O2 sensors, replaced the cam shaft sensor, and replaced all 8 spark plugs-- the issue has persisted.
I went over there tonight to use my bluetooth OBD2 scanner to grab the codes. I am not a mechanic but enjoy learning about vehicles and how they work. First off, the vehicle runs rough at idle and under RPM load. It honestly doesn't run terrible, but it doesn't run great either. I hooked up my scanner and connected it to my Android tablet. Here were my findings:
P0174- Powertrain
System too Lean (Bank2)
P0208- Powertrain
Injector Circuit - Cylinder 8
P0301- Powertrain
Cylinder 1 Misfire Detected
P0352- Powertrain
Ignition Coil ‘B’ Primary/Secondary Circuit
I cleared the codes and re-scanned after the car had been idling for 5 minutes:
P0208- Powertrain
Injector Circuit- Cylinder 8
P0301- Powertrain
Cylinder 1 Misfire Detected
Raw Data:
Fuel Rail Pressure: 38 PSI
Mass Airflow Sensor Rate: 5.31 g/s
02 Sensor 1: .72 Volts
02 Sensor 2: .78 Volts
02 Sensor 5: .11 Volts
02 Sensor 6: .12 Volts
Fuel Trim Bank 1 Short: -8.59%
Fuel Trim Bank 1 Long: -4.69%
Fuel Trim Bank 2 Short: 21.09%
Fuel Trim Bank 2 Long: 25%
Now, based upon what I have learned is that the 02 sensors should 'loop' from low voltage state to a higher voltage state. Two of the sensors stayed at .1-.12 Volts while the other two stayed around .75 Volts.
Additionally, the fuel trim for banks 1 and 2 appear to fluctuate a bit, but the values above are after the vehicle had been warmed up and running for 5-10 minutes. Based upon the values for Bank 1 I would say it's running a bit rich while Bank 2 is running extremely lean. We upped the RPMs and bank 2's fuel trim did not get any better, so the mechanic who said there were no vacuum leaks may have been correct.
So, after all is said I am not sure what to recommend that my Uncle check next. I was thinking of maybe checking the resistance on the 8th cylinder's fuel injector.
Does anyone have any recommendations? I am truly stumped. Thank you!
