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  #1  
Old 09-05-2015, 09:53 PM
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Random Cyclinder Misfires

I am getting random misfires on cylinders 2, 4, 6, 8 which are all on the same side of the engine, passenger side.

4.7L V8

What conditions would affect all cylinders on one side?

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  #2  
Old 09-11-2015, 06:58 AM
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Re: Random Cyclinder Misfires

I would check the fuel trim and voltage on the 2-1 O2 sensor. A bad O2 sensor can cause a downtrim of the fuel injector pulse in such a way that the mixture will simply not burn anymore. So if you have a scanner with live data, check the 2-1 O2 sensor voltage. It should go from 0.2V to 0.8 V and change constantly. If it indicates a fixed voltage, than the O2 sensor is bad. You will than also see a high negative fuel trim on the 2-1 sensor. (probably somewhere between -20 and -30)
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Old 09-12-2015, 11:45 AM
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Re: Random Cyclinder Misfires

Here is the test result, but I'm not sure how to read it.

Any help or advice would be appreciated.

Mode $06 report generated by Torque for Android
================================================

Vehicle VIN: Not present
Vehicle Manufacturer: Unknown
Vehicle Calibration ID: Not present

Test report:
------------------
MID:$01 TID:$91
- O2 Bank 1 Sensor 1
Max: 655.34998% Min: 0.83%
Test result value: 1.63%
PASS
----
MID:$02 TID:$07
Minimum sensor Voltage for test cycle(calculated) - O2 Bank 1 Sensor 2
Max: 0.392V Min: 0V
Test result value: 0.392V
PASS
----
MID:$02 TID:$08
Maximum sensor Voltage for test cycle(calculated) - O2 Bank 1 Sensor 2
Max: 65.535V Min: 0.705V
Test result value: 0.705V
PASS
----
MID:$02 TID:$81
- O2 Bank 1 Sensor 2
Test incomplete or dependant test failed
--
MID:$02 TID:$82
- O2 Bank 1 Sensor 2
Test incomplete or dependant test failed
--
MID:$02 TID:$83
- O2 Bank 1 Sensor 2
Test incomplete or dependant test failed
--
MID:$05 TID:$91
- O2 Bank 2 Sensor 1
Max: 655.34998% Min: 0.89%
Test result value: 1.68%
PASS
----
MID:$06 TID:$07
Minimum sensor Voltage for test cycle(calculated) - O2 Bank 2 Sensor 2
Max: 0.392V Min: 0V
Test result value: 0.156V
PASS
----
MID:$06 TID:$08
Maximum sensor Voltage for test cycle(calculated) - O2 Bank 2 Sensor 2
Max: 65.535V Min: 0.705V
Test result value: 0.705V
PASS
----
MID:$06 TID:$81
- O2 Bank 2 Sensor 2
Test incomplete or dependant test failed
--
MID:$06 TID:$82
- O2 Bank 2 Sensor 2
Test incomplete or dependant test failed
--
MID:$06 TID:$83
- O2 Bank 2 Sensor 2
Test incomplete or dependant test failed
--
MID:$10 TID:$2c
- O2 Bank 4 Sensor 4
Max: 819.20001AFR Min: 1,332AFR
Test result value: 3,276AFR
FAIL
----


End of report.
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  #4  
Old 09-12-2015, 11:52 AM
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Re: Random Cyclinder Misfires

I also have no idea what the testresult in % means. The 2-1 sensor (upstream sensor for bank 2, which is used for the fuel trim) shows almost the same value as the 1-1 sensor ( upstream sensor bank 1).
Can you go to live data and check the 2-1 sensor voltage? Also have a look at the STFT (short term fuel trim) for the 2-1 sensor.
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