Dodge Ram Truck 1500-2500-3500. Manual - part 1201

P0301-CYLINDER #1 MISFIRE (CONTINUED)

FUEL PRESSURE LEAK DOWN

NOTE: Before continuing visually and physically inspect the fuel delivery system for external leaks or dam-
age. Repair / replace as necessary.
Turn the ignition off.

WARNING: The fuel system is under a constant pressure (even with the engine off). Before testing or ser-
vicing any fuel system hose, fitting or line, the fuel system pressure must be released. Failure to follow
these instructions can result in personal injury or death
Install special tool #6539 (5/16

) or #6631 (3/8

) fuel line adapter.

Install the fuel pressure gauge.

Start the engine and allow the fuel system to reach maximum pressure.

Turn the ignition off.

NOTE: Fuel specification is 407 KPa +/- 34 KPa (59 psi +/- 5 psi).
Using special tool #C4390, Hose Clamp Pliers, pinch the rubber fuel line between the fuel pressure gauge and the
engine.

Monitor the fuel pressure gauge for a minimum of 5 minutes.

NOTE: The pressure should not fall below 241 KPa (35 psi).

Does the pressure fall below the listed specification?

Yes

>> Replace the leaking Fuel Injector(s).

Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

>> Go To 8

FUEL INJECTOR OPERATION

CAUTION: After each Fuel Injector actuation, start the engine to clean the cylinder of fuel. Failure to do so
could cause engine damage.
Remove special tool #C4390.

Start the engine and allow the fuel pressure to reach maximum pressure.

Ignition on, engine not running.

Using the scan tool, actuate the Fuel Injector.

Monitor the fuel pressure gauge.

Does the fuel pressure gauge indicate a drop in fuel pressure?

Yes

>> Go To 9

>> Go To 10

NOTE: Turn the ignition off, remove the Fuel Pressure gauge, and connect the fuel lines before continuing.

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ENGINE - ELECTRICAL DIAGNOSTICS - SRT-10

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P0301-CYLINDER #1 MISFIRE (CONTINUED)

ENGINE MECHANICAL

Check for any of the following conditions/mechanical problems.

ENGINE VACUUM - must be at least 13 inches in neutral

ENGINE VALVE TIMING - must be within specifications

ENGINE COMPRESSION - must be within specifications

ENGINE EXHAUST SYSTEM - must be free of any restrictions or leaks.

ENGINE PCV SYSTEM - must flow freely

TORQUE CONVERTER STALL SPEED - must be within specifications

POWER BRAKE BOOSTER - no internal vacuum leaks

FUEL - must be free of contamination

CAM LOBES - must not be worn excessively

CYLINDER LEAKAGE TEST - must be within specifications

VALVE SPRINGS - cannot be weak or broken

Are there any engine mechanical problems?

Yes

>> Repair as necessary.

Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

>> Go To 17

10.

FUEL INJECTOR

Turn the ignition off.

Disconnect the Fuel Injector harness connector.

Ignition on, engine not running.

NOTE: When a Misfire is detected for a particular cylinder, the
PCM will shut down that cylinders Injector Control circuit.
With the scan tool, erase DTCs.

Using a 12-volt test light connected to 12-volts, probe the (K11) Injec-
tor Control No.1 circuit.

With the scan tool, actuate the Fuel Injector.

Does the test light blink/flicker?

Yes

>> Replace the Fuel Injector.

Perform the POWERTRAIN VERIFICATION TEST. (Refer
to 9 - ENGINE - STANDARD PROCEDURE)

>> Go To 11

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P0301-CYLINDER #1 MISFIRE (CONTINUED)

11.

(K11) INJECTOR CONTROL CIRCUIT

Turn the ignition off.

Disconnect the PCM harness connector.

Check the (K11) Injector Control circuit for an open or short to ground.

Was a problem found with the Injector Control circuit?

Yes

>> Repair the excessive resistance or short in the (K11) Injec-

tor Control circuit.

Perform the POWERTRAIN VERIFICATION TEST. (Refer
to 9 - ENGINE - STANDARD PROCEDURE)

>> Go To 17

12.

FUEL SUPPLY LINE RESTRICTED

Turn the ignition off.

Install special tool #6539 (5/16

) #6631(3/8

) fuel line adapter and the fuel pressure gauge between the fuel supply

line and the fuel pump module.

Ignition on, engine not running.

With the scan tool, actuate the ASD Fuel System test and observe the fuel pressure gauge.

NOTE: Fuel pressure specification is 379 KPa +/- 14 KPa (55 psi +/- 2 psi).

Is the fuel pressure within specification?

Yes

>> Repair or replace fuel supply line as necessary.

Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

>> Go To 13

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ENGINE - ELECTRICAL DIAGNOSTICS - SRT-10

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P0301-CYLINDER #1 MISFIRE (CONTINUED)

13.

FUEL PUMP INLET STRAINER

Turn the ignition off.

Is the Fuel Inlet Strainer plugged?

Yes

>> Replace the Fuel Pump Inlet Strainer.

Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

>> Before continuing, check the Fuel Pump Module harness connector terminals for corrosion, damage, or

terminal push out. Make sure the ground circuit is functional. Repair as necessary. Replace the Fuel
Pump Module.

Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

14.

IGNITION WIRE

NOTE: If the vehicle being tested does not have an ignition wire answer YES to this test and continue.
Turn the ignition off.

Remove the ignition wire.

Measure the resistance of the ignition wire.

Is the resistance below 10K ohms?

Yes

>> Go To 15

>> Replace the Ignition Wire.

Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

15.

IGNITION COIL

Disconnect the Ignition Coil harness connector.

Remove the Fuel Pump Relay.

Using a 12-volt test light connected to 12-volts, probe the (K19) Igni-
tion Coil Control No.1 circuit.

Crank the engine for 5 seconds while observing the test light.

NOTE: The primary resistance of the 8.3L Ignition coil is 0.53 to
0.65 of an ohm at 77°F (25°C).

Does the test light brightly blink/flicker?

Yes

>> Replace the Ignition Coil.

Perform the POWERTRAIN VERIFICATION TEST. (Refer
to 9 - ENGINE - STANDARD PROCEDURE)

>> Go To 16

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