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

Description

The diagnostic table identifies a condition that causes an engine to not start. The diagnostic table directs the service technician to the appropriate system diagnosis. The diagnostic table assumes the following conditions are met:

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

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

•	There is adequate fuel in the fuel tank.

Diagnostic Aids

Inspect for the following conditions:

•

The mass air flow (MAF) is compared to a calculated mass air flow based upon the manifold absolute pressure (MAP), the throttle position (TP), and the engine RPM. A skewed or unresponsive MAP sensor at key on will cause the predicted air flow value to be inaccurate. Compare the MAP and TP readings to that of a known good vehicle.

•	A faulty engine coolant temperature (ECT) sensor. Use a scan tool in order to compare the ECT with the intake air temperature (IAT) on a completely cooled engine. The ECT should be within 3°C (5°F) of the IAT.

•	For an intermittent condition, refer to Intermittent Conditions .

Test Description

The number below refers to the step number on the diagnostic table.

This step verifies the IGN relay for proper operation. The IGN relay supplies voltage to the injectors and to the ignition coils. When the IGN relay is not operating properly, a no start condition occurs. If the test lamp does not illuminate, this indicates the IGN relay is not suppling a voltage to the fuses.

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

Crank the engine for the specified amount of time.

Does the scan tool display any DTCs that failed this ignition?

15 seconds

Go to Diagnostic Trouble Code (DTC) List

Go to Step 3

Inspect the body control module (BCM) for DTCs related to the vehicle theft deterrent (VTD) system.

Does the scan tool display any BCM vehicle theft deterrent DTCs?

Go to Diagnostic System Check - Theft Deterrent in Theft Deterrent

Go to Step 4

Monitor the engine speed while cranking the engine.

Is engine RPM indicated on the scan tool?

Go to Step 5

Go to DTC P0335

Turn ON the ignition, with the engine OFF.
Probe both sides of the fuses located in the underhood electrical center listed below using a test lamp connected to ground.

•

INJR 1

•

INJR 2

•

ECM I

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

Go to Step 6

Go to Ignition Relay Diagnosis

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

Does the HEI Spark Tester spark?

Go to Step 7

Go to Electronic Ignition (EI) System Diagnosis

Use the scan tool in order to monitor the engine coolant temperature (ECT).

Is the ECT on the scan tool close to the actual engine temperature?

Go to Step 8

Go to DTC P0118

Use the scan tool in order to enable the fuel pump.

Does the fuel pump operate?

Go to Step 9

Go to Fuel Pump Electrical Circuit Diagnosis

Turn OFF the ignition.
Install a fuel pressure gauge. Refer to Fuel Pressure Gage Installation and Removal .

Important: The fuel pump operates for about 2 seconds when the ignition is turned ON. The fuel pressure must be observed when the fuel pump is operating.

Turn ON the ignition, with the engine OFF.
Observe the fuel pressure while the fuel pump is operating.

Is the fuel pressure within the specified range?

379-427 kPa (55-62 psi)

Go to Step 10

Go to Fuel System Diagnosis

Perform the following additional inspections:

•	Inspect the duct work between the mass air flow (MAF) sensor and the throttle body for air leaks.

•	Ensure that the throttle angle is at 0 percent at a closed throttle. If the throttle angle is not at 0 percent , refer to DTC P0122 or DTC P0123 .

•

A malfunctioning MAF sensor may cause a no start or a stall after a start. If you suspect this, disconnect the MAF sensor. The PCM will default to the speed density in order to calculate the engine load and the intake air flow. If disconnecting the MAF sensor corrects the condition and the connections are OK, replace the MAF sensor. Refer to Mass Airflow Sensor Replacement .

•	Inspect the spark plugs for gas fouling. Refer to Spark Plug Inspection in Engine Electrical.

•	Inspect for an engine mechanical failure, such as timing chain, low compression. Refer to Engine Compression Test in Engine Mechanical.

•	Compare the MAP/BARO parameters to another vehicle. The parameter values should be close to each other.

Did you find and correct the condition?

Go to Step 11

Go to Hard Start

Use the scan tool in order to select the Diagnostic Trouble Codes (DTC) option and the Clear DTC Information.
Attempt to start the engine.

Does the engine start and continue to run?

Go to Step 12

Go to Step 2

Idle the engine at the normal operating temperature.
Use the scan tool in order to select the Diagnostic Trouble Code (DTC) option using the scan tool.

Are any DTCs displayed?

Go to Diagnostic Trouble Code (DTC) List

Go to Step 13

Use the scan tool in order to select the Capture Info option and the Review Info option.

Are any DTCs displayed that you have not diagnosed?

Go to Diagnostic Trouble Code (DTC) List

System OK