Engine Cranks But Does Not Run. Pontiac Firebird 2002

For 1990-2009 cars only

Makes 🢒 Pontiac 🢒 2002 🢒 Firebird 🢒 Engine 🢒 Engine Electrical 🢒 Engine Cranks But Does Not Run

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.

•	There is adequate fuel in the tank.

•	There is proper compression.

Step

Action

Values

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, P0602, P0604, P0606, P1626, or P1629 set?

Go to Diagnostic Trouble Code (DTC) List

Go to Step 3

Turn ON the ignition, with the engine OFF.
Test both sides of each of the following fuses with a test lamp connected to ground.

•

ENG CTRL

•	Fuel injectors

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

Go to Step 4

Go to Ignition Relay Diagnosis

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 5

Go to Electronic Ignition (EI) System 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?

333-376 kPa

(48-55 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 9

Go to Step 8

Remove the J 34730-405 Fuel Injector Test Lamp from the fuel injector connector.
Turn ON the ignition, with the engine OFF.
Probe the ignition 1 voltage supply circuit of the fuel injector with a test lamp connected to ground.

Does the test lamp illuminate?

Go to DTC P0341

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.
Start the engine.

Does the spark tester spark?

Go to Step 10

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, or low compression--Refer to Engine Compression Test in Engine Mechanical.

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

•	Faulty engine coolant temperature (ECT) sensor

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

•	Stuck throttle position (TP) sensor

Did you complete the action?

Go to Step 11

Clear the DTCs with a scan tool.
Start the engine.

Does the engine start and continue to operate?

Go to Step 12

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 13

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