Engine Cranks But Does Not Run. Buick Regal 2002

For 1990-2009 cars only

Makes 🢒 Buick 🢒 2002 🢒 Regal 🢒 Engine 🢒 Engine Controls - 3.8L 🢒 Engine Cranks But Does Not Run

Engine Cranks But Does Not Run with Supercharger

Circuit Description

Conditions that may cause an Engine Cranks but Does Not Run symptom include a lack of the following items.

•	Fuel in the proper amount, quality, and at the proper time

•	Spark of the proper quality and at the proper time

•	Proper compression

The following table will isolate the failed system and lead to the correct diagnostic procedure.

Diagnostic Aids

Use a scan tool in order to compare engine coolant temperature (ECT) with intake air temperature (IAT) on a completely cool engine. ECT should be within 10°C (50°F) of IAT.

Step

Action

Value(s)

Yes

Schematic Reference: Engine Controls Schematics

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.
Use a scan tool in order to observe the DTC information.

Does the scan tool display DTCs P0230, P0336, P0601, or P0602?

Go to Diagnostic Trouble Code (DTC) List

Go to Step 3

Attempt to start the engine.
Use a scan tool in order to monitor the engine RPM parameter while the engine is cranking.

Does the engine RPM parameter display cranking RPM?

Go to Step 4

Go to Electronic Ignition (EI) System Diagnosis

Turn ON the ignition, with the engine OFF.

Important: Ensure the fuses listed below are not open, before proceeding with this test.

Probe both sides of the following fuses:

•

PCM

•

Fuel Pump

•	Fuel Injectors

•	Ignition Module

Does the test lamp illuminate on both sides of all the fuses listed?

Go to Step 5

Go to Ignition Relay Diagnosis

Use a scan tool in order to command the fuel pump ON.

Does the fuel pump turn ON?

Go to Step 6

Go to Fuel Pump Electrical 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.
Use a scan tool in order to command the fuel pump ON.

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 7

Go to Fuel System Diagnosis

Turn OFF the ignition.
Disconnect an injector connector.
Install the J 34730-405 Injector Test Lamp (L36) or 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.
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 9

Go to Electronic Ignition (EI) 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, such as worn timing chain and gears, low compression--Refer to Engine Compression Test in Engine Mechanical 3.8L.

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

•	The ECT sensor is NOT close to the actual engine temperature.

•	Compare manifold absolute pressure/barometric pressure (MAP/BARO) parameters to another vehicle. The parameters should be close in value--Refer to Manifold Absolute Pressure Sensor Diagnosis .

•	The throttle position (TP) sensor for being stuck in range.

Did you find and correct the condition?

Go to Step 10

Go to Diagnostic Aids

Use a scan tool in order to clear the DTCs.
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.
Use a scan tool in order to observe the DTC information.

Are any DTCs displayed?

Go to Diagnostic Trouble Code (DTC) List

Go to Step 12

With a scan tool, observe the stored information, Capture Info.

Does the scan tool display any DTCs that you have not diagnosed?

Go to Diagnostic Trouble Code (DTC) List

System OK

Engine Cranks But Does Not Run without Supercharger

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.

•	There is proper compression. Refer to Engine Compression Test in Engine Mechanical.

•	There is adequate fuel in the fuel tank.

Step

Action

Value(s)

Yes

Schematic Reference: Engine Controls Schematics

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 P0230, P0336, P0341, P0601, or P0602 set?

Go to Diagnostic Trouble Code (DTC) List

Go to Step 3

Monitor the engine RPM parameter with a scan tool, while the engine is cranking.

Does the engine RPM parameter display cranking RPM?

Go to Step 4

Go to Electronic Ignition (EI) System Diagnosis

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:

•

PCM

•	Fuel Injectors

•	Ignition Module

Does the test lamp illuminate on at least one side of all the fuses listed?

Go to Step 5

Go to Ignition Relay Diagnosis

Command the fuel pump relay ON with a scan tool.

Does the fuel pump run?

Go to Step 6

Go to Fuel Pump Electrical 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 7

Go to Fuel System Diagnosis

Turn OFF the ignition.
Disconnect a fuel injector connector.
Install the J 34730-405 Fuel Injector Test Lamp 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.
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 9

Go to Electronic Ignition (EI) 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, such as worn timing chain and gears, low compression--Refer to Engine Compression Test in Engine Mechanical.

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

•	Faulty ECT sensor

•	Faulty MAP sensor--Refer to Manifold Absolute Pressure Sensor Diagnosis .

•	Stuck TP sensor

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

Go to Step 12

Observe the Capture Info with a scan tool.

Are there any DTCs that have not been diagnosed?

Go to Diagnostic Trouble Code (DTC) List

System OK