GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2001 🢒 Savana 🢒 Engine 🢒 Engine Controls - 8.1L 🢒 Engine Cranks But Does Not Run

Description

The Engine Cranks but Does Not Run diagnostic table is an organized approach to identifying a condition that prevents an engine from starting. 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.
    • The cranking speed is within specifications.
    • There is adequate fuel in the fuel tank.

Diagnostic Aids

Inspect for the following conditions:

    • Mass air flow (MAF) is compared to a calculated mass air flow based upon the manifold absolute pressure (MAP), throttle position (TP), and engine RPM readings. A skewed or unresponsive MAP sensor at KEY ON will cause the predicted air flow value to be inaccurate. Compare MAP and TP sensor values to that of a known good vehicle.
    • Faulty ECT sensor. Using a scan tool, compare engine coolant temperature with intake air temperature (IAT) on a completely cool engine. ECT should be within 3 C (5 F) of the intake air temperature.
        For an intermittent condition, refer to Intermittent Conditions .

Step

Action

Values

Yes

No

1

Did you perform A Diagnostic System Check-Engine Controls?

--

Go to Step 2

Go to Diagnostic System Check - Engine Controls

2
  1. Turn ON the ignition, with the engine OFF.
  2. Observe the DTC information with a scan tool.

Does the scan tool display DTC P0230, P0335, P0336, P0601, P0602, P0604, P0606, P1626, P1631, P1683, B2960?

--

Go to Diagnostic Trouble Code (DTC) List

Go to Step 3

3
  1. Attempt to start the engine.
  2. 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

4

Command the fuel pump ON with a scan tool.

Does the fuel pump turn ON?

--

Go to Step 5

Go to Fuel Pump Electrical Circuit Diagnosis

5
  1. Turn OFF the ignition.
  2. Install the J 34730-1A Fuel Pressure Gauge. Refer to Fuel Pressure Gage Installation and Removal .
  3. Turn ON the ignition, with the engine OFF.
  4. Command the fuel pump ON with a scan tool.

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

384-425 kPa

(55-62 psi)

Go to Step 6

Go to Fuel System Diagnosis

6
  1. Turn OFF the ignition.
  2. Disconnect an injector connector.
  3. Install the J 34730-405 Injector Test Lamp to the injector connector.
  4. Attempt to start the engine.

Does the test lamp blink while the engine is cranking?

--

Go to Step 7

Go to DTC P0200

7
  1. Turn OFF the ignition.
  2. Disconnect a spark plug wire.
  3. Install the J 26792 Spark Tester to the spark plug wire.
  4. Attempt to start the engine.

Does the spark tester spark?

--

Go to Step 8

Go to Electronic Ignition (EI) System Diagnosis

8

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.
    • Restricted exhaust system. Refer to Restricted Exhaust in Engine Exhaust.
    • The engine coolant temperature (ECT) sensor is NOT close to the actual engine temperature.
    • Compare MAP/ barometric pressure (BARO) parameters to another vehicle. The parameters should be close in value.

Did you find and correct the condition?

--

Go to Step 9

Go to Diagnostic Aids

9
  1. Clear the DTCs with a scan tool.
  2. Attempt to start the engine.

Does the engine start and continue to operate?

--

Go to Step 10

Go to Step 2

10
  1. Idle the engine.
  2. Allow the engine to reach operating temperature.
  3. Observe the DTC information with a scan tool.

Are any DTCs displayed?

--

Go to Diagnostic Trouble Code (DTC) List

Go to Step 11

11

Observe the Capture Info with a scan tool.

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

--

Go to Diagnostic Trouble Code (DTC) List

System OK