Engine Cranks But Does Not Run. Buick Regal 2004

For 1990-2009 cars only

Makes 🢒 Buick 🢒 2004 🢒 Regal 🢒 Engine 🢒 Engine Electrical 🢒 Engine Cranks But Does Not Run

Engine Cranks But Does Not Run with Supercharger

Circuit Description

The Engine Cranks But Does Not Run diagnostic table is an organized approach to identifying a condition that causes an engine not to start. The Engine Cranks But Does Not Run diagnostic table directs the service technician to the appropriate system diagnosis.

The Engine Cranks But Does Not Run diagnostic table assumes the following:

•	The battery is completely charged. Refer to Battery Inspection/Test in Engine Electrical.

•	The engine cranking speed is acceptable. Refer to Engine Cranks Slowly in Engine Electrical.

•	There is adequate fuel in the fuel tank

Step

Action

Values

Yes

Schematic Reference: Engine Controls Schematics

Connector End View Reference: Engine Controls Connector End Views or Powertrain Control Module Connector End Views

Did you perform the Diagnostic System Check-Engine Controls?

Go to Step 2

Go to Diagnostic System Check - Engine Controls

Turn ON the ignition, with the engine OFF.
Observe the DTC information with a scan tool.

Does the scan tool display DTC P0101, P0123, P0230, P0336, P0601, P0602, P1626, P1631, or P2610?

Go to Diagnostic Trouble Code (DTC) List

Go to Step 3

Turn ON the ignition with the engine OFF.
Probe both sides of the INJ fuse and the ELEK fuse with a test lamp connected to a good ground.

Does the test lamp illuminate on at least one side of each fuse?

Go to Step 4

Go to Ignition Relay Diagnosis

Attempt to start the engine.
Observe the engine speed parameter while the engine is cranking with a scan tool.

Does the engine speed parameter display cranking RPM?

Go to Step 5

Go to Electronic Ignition (EI) System Diagnosis

Command the fuel pump ON, with a scan tool.

Does the fuel pump turn ON?

Go to Step 6

Go to Fuel Pump Electrical Circuit Diagnosis

Turn OFF the ignition.
Disconnect a spark plug wire.
Install the J 26792 Spark Tester to the spark plug wire.
Attempt to start the engine.

Does the spark tester spark?

Go to Step 7

Go to Electronic Ignition (EI) System Diagnosis

Turn OFF the ignition.
Disconnect an injector connector.
Install the J 34730-2C TBI Harness Test Lamp (L67) to the injector connector.
Attempt to start the engine.

Does the test lamp blink while the engine is cranking?

Go to Step 8

Go to Fuel Injector Circuit Diagnosis

Turn OFF the ignition.
Install the J 34730-1A Fuel Pressure Gage. Refer to Fuel Pressure Gage Installation and Removal .
Turn ON the ignition, with the engine OFF.
Command the fuel pump ON with a scan tool.

Is the fuel pressure within the specified range while the fuel pump is operating?

364-405 kPa (53-59 psi) VIN K

336-375 kPa (48-54 psi) VIN 1

Go to Step 9

Go to Fuel System Diagnosis

Inspect for the following conditions:

•	Collapsed air intake duct

•	Restricted air filter element--Refer to Air Cleaner Element Replacement .

•	Spark plugs for being gas or coolant fouled--Refer to Spark Plug Inspection . If the spark plugs are fouled, determine what caused the condition.

•	Engine mechanical condition (worn timing chain and gears, low compression, etc.)--Refer to Symptoms - Engine Mechanical in Engine Mechanical 3.8L.

•	Restricted exhaust system--Refer to Restricted Exhaust in Engine Exhaust.

•	Faulty engine coolant temperature (ECT) sensor

•	Faulty manifold absolute pressure (MAP) sensor--Refer to Manifold Absolute Pressure Sensor Diagnosis .

•	Stuck throttle position (TP) sensor--Refer to DTC P0121 .

Did you complete the action?

Go to Step 10

Clear the DTCs with a scan tool.
Attempt to start the engine.

Does the engine start and continue to operate?

Go to Step 11

Go to Step 2

Idle the engine.
Allow the engine to reach operating temperature.
Observe the DTC information with a scan tool.

Are any DTCs displayed?

Go to Diagnostic Trouble Code (DTC) List

System OK

Engine Cranks But Does Not Run without Supercharger

Circuit Description

The Engine Cranks but Does Not Run diagnostic table is an organized approach to identifying a condition that causes an engine not to start. The Engine Cranks but Does Not Run diagnostic table directs the service technician to the appropriate system diagnosis. The Engine Cranks but Does Not Run diagnostic table assumes the following:

•	The battery is completely charged. Refer to Battery Inspection/Test in Engine Electrical.

•	The engine cranking speed is acceptable. Refer to Engine Cranks Slowly in Engine Electrical.

•	There is adequate fuel in the fuel tank.

Step

Action

Values

Yes

Schematic Reference: Engine Controls Schematics

Connector End View Reference: Engine Controls Connector End Views or Powertrain Control Module Connector End Views

Did you perform the Diagnostic System Check-Engine Controls?

Go to Step 2

Go to Diagnostic System Check - Engine Controls

Turn ON the ignition, with the engine OFF.
Observe the DTC information with a scan tool.

Is DTC P0101, P0123, P0230, P0336, P0341, P0601, P0602, P1626, P1631 or P2610 set?

Go to Diagnostic Trouble Code (DTC) List

Go to Step 3

Turn ON the ignition, with the engine OFF.
Probe both sides of the following fuses with a test lamp that is connected to a good ground:

•

INJ

•

ELEK Fuse

Does the test lamp illuminate on at least one side of each fuse?

Go to Step 4

Go to Ignition Relay Diagnosis

Observe the engine speed parameter with a scan tool, while the engine is cranking.

Does the engine speed parameter display cranking RPM?

Go to Step 5

Go to Electronic Ignition (EI) System Diagnosis

Command the fuel pump relay ON with a scan tool.

Does the fuel pump turn ON?

Go to Step 6

Go to Fuel Pump Electrical Circuit Diagnosis

Turn OFF the ignition.
Disconnect a spark plug wire.
Install the J 26792 Spark Tester to the spark plug wire.
Attempt to start the engine.

Does the spark tester spark?

Go to Step 7

Go to Electronic Ignition (EI) System Diagnosis

Turn OFF the ignition.
Disconnect a fuel injector connector.
Install the J 34730-405 Fuel Injector Test Lamp (L36) to the fuel injector connector.
Attempt to start the engine.

Does the test lamp blink while the engine is cranking?

Go to Step 8

Go to Fuel Injector Circuit Diagnosis

Turn OFF the ignition.
Install the J 34730-1A Fuel Pressure Gage. Refer to Fuel Pressure Gage Installation and Removal .
Turn ON the ignition, with the engine OFF.
Command the fuel pump relay ON with a scan tool.

Is the fuel pressure within the specified range while the fuel pump is operating?

364-405 kPa (53-59 psi)

Go to Step 9

Go to Fuel System Diagnosis

Inspect for the following conditions:

•	Collapsed air intake duct

•	Restricted air filter element--Refer to Air Cleaner Element Replacement .

•	Fouled spark plugs--Refer to Spark Plug Inspection . If the spark plugs are fouled, determine what caused the condition.

•	Engine mechanical condition (worn timing chain and gears, low compression, etc.)--Refer to Symptoms - Engine Mechanical in Engine Mechanical 3.8L.

•	Restricted exhaust system--Refer to Restricted Exhaust in Engine Exhaust.

•	Faulty engine coolant temperature (ECT) sensor

•	Faulty manifold absolute pressure (MAP) sensor--Refer to Manifold Absolute Pressure Sensor Diagnosis .

•	Stuck throttle position (TP) sensor--Refer to DTC P0121 .

Did you complete the action?

Go to Step 10

Clear the DTCs with a scan tool.
Attempt to start the engine.

Does the engine start and continue to operate?

Go to Step 11

Go to Step 2

Idle the engine.
Allow the engine to reach operating temperature.
Observe the DTC information with a scan tool.

Are any DTCs displayed?

Go to Diagnostic Trouble Code (DTC) List

System OK