Truck has done it twice 3 weeks apart rough idle at start that fades after driving 5 minutes.

Pulls code P0302 which is cylinder 2 misfire and check engine light is on.

Will this clear itself or should I take it in?

Does this indicate a bad injector?



I'm fretting over this as I'm movong to NC and will be driving family in truck.

thanks fellas

 

99.9% bad injector. Don't drive it like that you can score cylinder bore quick. Dealer should stock new sticks. Do this if truck is under warranty.

 

P0302 is a injector not opening up due to bad solenoid

 

P302 only says that the computer is seeing a misfire on cylinder #2. It can be anything from injector, valve, dropped valve seat, broken valve spring, burned piston. Tons of things. Yeah, most likely an injector, but nothing is set in stone. Too many variables.

 

Just wondering how would the ecm be able to tell a burnt piston,bad valve when the only thing being monitored by the ecm is the solenoid of the injector. I had two cracked injectors and flooded the engine with fuel and I am still waiting for the check engine light to come on??

 

This should help to explain.

The Powertrain Control Module (PCM) monitors for misfire during most engine operating conditions (positive torque) by looking at changes in the crankshaft speed. If a misfire occurs the speed of the crankshaft will vary more than normal.




P0302-CYLINDER # 2 MISFIRE
For a complete wiring diagram Refer to Section 8W.

When Monitored:
While the engine is idling at operating temperature.

Set Condition:
Misfire detected on this cylinder.

Possible Causes
LOW FUEL
OTHER DTC'S
DAMAGED FUEL LINE
VALVE TRAIN
OBSTRUCTED FUEL INJECTOR SUPPLY LINE
DAMAGED OR OBSTRUCTED HIGH PRESSURE CONNECTOR
EXTERNAL DAMAGED FUEL INJECTOR
INTERNAL DAMAGED FUEL INJECTOR
NO COMPRESSION
EXCESSIVE ENGINE LEAK DOWN


Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)

Diagnostic Test
1. LOW FUEL

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Using the scan tool, verify that the fuel level is above 15%.

Is the fuel level above 15%?

Yes
Go To 2

No
Add fuel go to step 2.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES/ENGINE CONTROL MODULE - DIAGNOSIS AND TESTING)



2. OTHER DTC'S

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Read the Freeze frame data.

Is the DTC equal to the freeze frame DTC?

Yes
Go To 3

No
Repair any other DTC's first.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES/ENGINE CONTROL MODULE - DIAGNOSIS AND TESTING)



3. DAMAGED FUEL LINE

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Visually inspect the injector supply line for damage.

Do you have any kinked or bent fuel line?

Yes
Repair or replace the damaged fuel line.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES/ENGINE CONTROL MODULE - DIAGNOSIS AND TESTING)

No
Go To 4



4. VALVE TRAIN

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Visually inspect the valve train and check the valve lash on the suspect cylinder.

Is the valve train functional and the lash within the specifications listed in the service manual?

Yes
Go To 5

No
Adjust the lash or fix or repair any damaged component(s).
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES/ENGINE CONTROL MODULE - DIAGNOSIS AND TESTING)



5. OBSTRUCTED FUEL INJECTOR SUPPLY

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Remove the fuel injector supply line for the suspect cylinder.
Inspect both ends of the fuel injector supply line for damage.
Using shop air pressure, blow out the fuel injector supply line to verify that they are not obstructed.

Are the fuel lines free of debris or damage?

Yes
Go To 6

No
Replace the damaged or obstructed fuel injector supply line.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES/ENGINE CONTROL MODULE - DIAGNOSIS AND TESTING)



6. DAMAGED OR OBSTRUCTED HIGH PRESSURE CONNECTOR

--------------------------------------------------------------------------------
Remove the high pressure connector for the suspect cylinder.
Inspect both ends of the high pressure connector for signs of damage.
Using shop air pressure, blow out the high pressure connector to verify that it is not obstructed.

Are the high pressure connectors free of debris or damage?

Yes
Go To 7

No
Replace the damaged or obstructed high pressure connector.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES/ENGINE CONTROL MODULE - DIAGNOSIS AND TESTING)



7. FUEL INJECTOR

--------------------------------------------------------------------------------
Remove the suspect fuel injector.

Is the fuel injector damaged?

Yes
Replace the external damaged fuel injector & high pressure connector.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES/ENGINE CONTROL MODULE - DIAGNOSIS AND TESTING)

No
Go To 8



8. INTERNAL DAMAGED FUEL INJECTOR

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With the scan tool, erase DTCs.
Switch the misfiring injector & high pressure connector with an injector & high pressure connector from a cylinder that is firing properly.
Operate the vehicle.

Did the misfire DTC follow the suspect injector & high pressure connector?

Yes
Replace the internal damaged fuel injector and high pressure connector.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES/ENGINE CONTROL MODULE - DIAGNOSIS AND TESTING)

No
Go To 9



9. INTERNAL ENGINE DAMAGE

--------------------------------------------------------------------------------
Perform engine compression test

Did the suspect cylinders pass the compression test?

Yes
Go To 10

No
Repair the internal damage to the engine.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES/ENGINE CONTROL MODULE - DIAGNOSIS AND TESTING)



10. INTERNAL ENGINE DAMAGE

--------------------------------------------------------------------------------
Perform engine leak down test

Did the suspect cylinders pass the leak down test?

Yes
Test Complete.

No
Repair the internal damage to the engine.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES/ENGINE CONTROL MODULE - DIAGNOSIS AND TESTING)