GM Service Manual Online
For 1990-2009 cars only

Step

Action

Values

Yes

No

Important: Ensure that the driver is using the correct starting procedure. Before diagnosing, check service bulletins for updates.

DEFINITION: The engine cranks OK, but does not start for a long time. The engine eventually runs or may start and immediately die.

1

Were the Preliminary Checks performed?

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Go to Step 2

Go to Symptoms - Engine Controls

2

  1. Connect the scan tool to the data link connector (DLC).
  2. Inspect the engine coolant temperature (ECT) sensor and the intake air temperature (IAT) sensor using the scan tool.
  3. Compare the coolant temperature and the IAT with the ambient temperature when the engine is cold.

Do the ECT and the IAT readings differ from the ambient temperature greater than the value specified?

3°C (5°F)

Go to Step 3

Go to Step 4

3

  1. Measure the resistance of the ECT and the IAT sensor.
  2. Compare the resistance value to specifications using the Temperature vs. Resistance tables. Refer to Temperature Versus Resistance .
  3. If the resistance is not the same, replace the faulty sensor.

Did you find and correct the condition?

--

System OK

--

4

  1. Inspect for a sticking throttle shaft or a binding linkage that may cause a high throttle position (TP) sensor voltage. Repair or replace as needed.
  2. Inspect the TP sensor voltage reading with the throttle closed.

Does the voltage measure within the specified range?

0.4-0.8 V

Go to Step 5

Go to Step 26

5

  1. Inspect the manifold absolute pressure (MAP) sensor response and accuracy.
  2. Replace the MAP sensor, as needed.

Did you find and correct the condition?

--

System OK

Go to Step 6

6

Inspect the fuel pump operation.

Does the fuel pump operate for the specified time when the ignition switch is turned ON?

2 seconds

Go to Step 7

Go to Fuel Pump Electrical Circuit Diagnosis

7

Inspect the fuel system pressure.

Is the fuel pressure within the specified range?

279-393 kPa (55-57 psi)

Go to Step 8

Go to Step 29

8

Inspect for water contamination in the fuel.

Is fuel contaminated?

--

Go to Step 9

Go to Step 10

9

Replace the contaminated fuel.

Did you complete the replacement?

--

System OK

--

10

  1. Inspect the fuel injector driver circuit.
  2. Disconnect all of the fuel injector harness connectors at the fuel injectors.
  3. Connect an injector test light between the harness terminals of each fuel injector connector.
  4. Note the test light while cranking the engine.

Does the test light blink at all connectors?

--

Go to Step 13

Go to Step 11

11

Inspect the fuel injector driver wiring harness, the connectors, and the connector terminals for the proper connections.

Is a repair necessary?

--

Go to Step 12

Go to Step 30

12

Repair the wiring harness, the connector, or the connector terminal as needed.

Did you complete the repair?

--

System OK

--

13

Measure the resistance of each fuel injector at 20°C (68°F). The resistance will increase slightly at higher temperatures.

Is the fuel injector resistance within the specified range?

11.6-12.4 ohms

Go to Step 15

Go to Step 14

14

Replace any fuel injector with a resistance that is out of specifications.

Did you complete the replacement?

--

System OK

--

15

Perform an injector balance test. Refer to Fuel Injector Balance Test with Special Tool .

Is a repair necessary?

--

Go to Step 16

Go to Step 17

16

Replace any restricted or leaking fuel injectors as needed.

Did you complete the replacement?

--

System OK

--

17

  1. Measure for the proper ignition voltage output for each cylinder with a spark tester.
  2. Inspect the spark plugs for cracks, wear, improper gap, burned electrodes, or heavy deposits.
  3. Inspect the ignition wires for short conditions.
  4. Inspect all of the ignition grounds for loose connections.
  5. Inspect the powertrain control module (PCM)/engine control module (ECM) for the proper operation.

Is a repair necessary?

--

Go to Step 18

Go to Step 19

18

Correct or replace any faulty ignition components.

Did you complete the repair?

--

System OK

--

19

Does the engine misfire or cut out under load or at idle?

--

Go to Electronic Ignition (EI) System Diagnosis

Go to Step 20

20

Does the engine start, but then immediately stall?

--

Go to Step 21

Go to Step 23

21

  1. Remove the crankshaft position (CKP) sensor.
  2. Inspect for faulty connections and repair as needed.

Did you find and correct the condition?

--

Go to Step 22

Go to Step 25

22

Repair the faulty connections, as needed.

Did you complete the repair?

--

System OK

--

23

  1. Inspect for the proper valve timing.
  2. Inspect the cylinder compression.
  3. Inspect the pushrods, the rocker arms, the valve springs, and the camshaft lobes for excessive wear.
  4. Inspect the intake manifold and the exhaust manifold passages for casting flash.

Is a repair necessary?

--

Go to Step 24

Go to Step 25

24

Repair or replace any components as needed.

Did you complete the repair?

--

System OK

--

25

Inspect the idle air control (IAC) valve operation. Repair or replace components, as needed.

Did you find and correct the condition?

--

System OK

--

26

Inspect the base idle setting of the throttle body.

Did you find and correct the condition?

--

Go to Step 27

Go to Step 28

27

Inspect the TP sensor circuit for proper operation. Repair or replace components, as needed.

Did you find and correct the condition?

--

System OK

--

28

Adjust the base idle setting to specifications.

Is the repair complete?

--

System OK

--

29

Repair the fuel system, as needed.

Did you complete the repair?

--

System OK

--

30

Replace the ECM.

Did you complete the replacement?

--

System OK

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