Engine Cranks But Does Not Run. Geo Prizm 1996

For 1990-2009 cars

Schematic Reference: Engine Controls Schematics

### Circuit Description

When the ignition switch is turned to the ON or START positions, voltage is applied to the ignition coil and ignition control (IC) module (Igniter). When the IC module receives the command from the powertrain control module (PCM), the primary coil windings of the ignition coil are toggled ON and OFF. By toggling the windings ON and OFF, a high voltage is produced in the secondary coil windings. The induced high voltage is forced to find a ground path through the rotor and distributor cap to each secondary spark plug wire and spark plug.

### Diagnostic Aids

Check for any of the following conditions:

• | Check the battery condition and the engine cranking speed. The engine will not start and improper diagnosis may occur if the starting system is not operating to necessary levels. Refer to Starting System check in Engine Electrical.

• | Water or foreign material can cause a no start during freezing weather. The engine may start after 5 or 6 minutes in a heated shop. The malfunction may not recur until the vehicle is parked overnight in freezing temperatures.

• | Fouled or damaged spark plugs may cause an Engine Cranks But Will Not Run condition. Refer to Spark Plug Visual Diagnosis in Engine Electrical.

• | A vehicle that starts and runs after being brought to the shop for an Engine Cranks But Will Not Run complaint, may have an ignition system that is susceptible to moisture. Spray water on the ignition system components and wiring in order to check for an engine miss or stall.

• | Check for a malfunctioning EFI relay. A faulty EFI relay can cause no MIL and an engine that cranks but will not run.

An intermittent malfunction may be caused by a problem in the ignition system electrical circuit. Inspect the wiring harness and components for any of the following conditions:

• | Backed out terminals.

• | Improper mating of terminals.

• | Broken electrical connector locks.

• | Improperly formed or damaged terminals.

• | Faulty terminal to wiring connections.

• | Physical damage to the wiring harness.

• | Broken conductor inside the wire insulation.

• | Corrosion of electrical connections, splices, or terminals.

### Test Description

The numbers below refer to the step numbers in the diagnostic table.

1. The Powertrain OBD System Check prompts the technician to complete some basic checks and stores the freeze frame data on the scan tool if applicable. This creates an electronic copy of the data taken when the fault occurred. The information is then stored in the scan tool for later reference.

2. The PCM relies on the CMP sensor for engine reference. Without engine reference signals there is no spark and no fuel injector pulse.

3. If there is a fault in the primary ignition system circuits or the ignition control module, DTC P1300 sets.

4. This step checks the ECT sensorr for a faulty signal. A faulty sensor input to the PCM may cause a fueling condition that results in a no start.

5. This step checks the TP sensor for a faulty signal. A faulty sensor input to the PCM may cause a fueling condition that results in a no start.

6. This step checks the MAP sensor for a faulty signal. A faulty sensor input to the PCM may cause a fueling condition that results in a no start.

7. This step checks for adequate secondary ignition voltage at the spark plugs.

8. This step checks to see if fuel system pressure is within specifications with the ignition ON and the fuel pump running. The fuel pump may be operated with the scan tool Output Control feature when the fuel level is greater than 20%.

Step | Action | Values | Yes | No
--- | --- | --- | --- | ---
1 | Did you perform the Powertrain On-Board Diagnostic System Check? | -- | Go to Step 2 | Go to Powertrain On Board Diagnostic (OBD) System Check
2 | Check for DTCs with a scan tool. Is DTC P0335 or P0340 set? | -- | Go to DTC P0335 Crankshaft Position (CKP) Sensor Circuitor DTC P0340 Camshaft Position (CMP) Sensor Circuit | Go to Step 3
3 | Is DTC P1300 set? | -- | Go to DTC P1300 Ignition Coil 1 Primary Feedback Circuit | Go to Step 4

4

1. Turn ON the ignition, leaving the engine OFF.
2. Observe the ECT sensor parameter on the scan tool.

Is the coolant temperature displayed on the scan tool near the actual coolant temperature?

--

Go to Step 5

Go to DTC P0116 Engine Coolant Temperature (ECT) Sensor Performance

5 | Observe the TP sensor parameter on a scan tool with the throttle closed. Is the throttle position opening displayed on the scan tool within the specified value? | 0-23% | Go to Step 6 | Go to DTC P0121 Throttle Position (TP) Sensor Performance

6

1. Observe the MAP sensor kPa reading on the scan tool.
2. Compare the MAP kPa reading with the kPa reading of a known good vehicle.

Was the kPa reading of both vehicles within 2kPa of each other?

--

Go to Step 7

Go to DTC P0106 Manifold Absolute Pressure (MAP) System Performance

7

1. Disconnect the fuel injector electrical connectors.
2. Install a J 26792 spark tester or an equivalent to the #1 spark plug wire.
3. Check for spark while cranking the engine.
4. Re-install the spark plug wire and repeat Steps 2 thru 4 for each cylinder.

Did each spark plug wire have a good crisp blue spark while cranking the engine?

--

Go to Step 8

Go to Step 14

8

1. Turn OFF the ignition.
2. Install the J 34730-1A fuel pressure gauge or an equivalent. Refer to Fuel Pressure Gage Installation and Removal .

Important: In order to obtain maximum fuel pressure it may be necessary to cycle the ignition ON to OFF to ON more than once.

3. Turn ON the ignition, leaving the engine OFF (the fuel pump should run for approximately 2 seconds).
4. Observe the fuel pressure with the fuel pump running.

Is the fuel pressure indicated within the specified values?

265 to 304 kPa (38 to 44 psi)

Go to Step 10

Go to Step 9

9

1. Turn ON the ignition, leaving the engine OFF (the fuel pump should run for approximately 2 seconds).
2. Observe the fuel pressure.

Did the fuel pressure gauge indicate any pressure greater than the specified value?

0 to 7 kPa (0 to 1.0 psi)

Go to Fuel System Diagnosis

Go to Fuel System - Circuit Opening Relay Diagnosis

10

1. Check for contaminated fuel.
2. Repair as necessary.

Was a repair necessary?

--

Go to Step 20

Go to Step 11

11

1. Remove the spark plugs.
2. Visually and physically inspect the spark plugs for any of the following conditions:

• | Oil fouling

• | Fuel fouling

• | Evidence of coolant in the cylinder

• | Incorrect gap

• | Missing platinum pads

• | Loose center electrode

• | Cracked porcelain

• | Carbon tracking

• | Loose terminal end

3. Replace as necessary.

Did any of the spark plugs need replacement?

--

Go to Step 20

Go to Step 12

12

1. Turn OFF the ignition.
2. Disconnect all four fuel injector electrical connectors.
3. Install a J 34730-2B injector test lamp or an equivalent into each fuel injector harness connector.
4. Observe the injector test lamp for each injector while cranking the engine.

Did the injector test lamp flash for each injector while cranking the engine?

--

Go to Step 13

Go to Fuel Injector Circuit Diagnosis

13 | Check for faulty fuel injectors. Refer to Fuel Injector Solenoid Coil Test - Engine Coolant Temperature Between 10-35 Degrees C (50-95 Degrees F) and Fuel Injector Balance Test. Was a faulty fuel injector found and replaced? | -- | Go to Step 20 | Go to Step 18
14 | Measure the resistance of each spark plug wire. Is the resistance within the specified values? | 3.0k to 6.7k ohms per ft. | Go to Step 15 | Go to Step 19

15

1. Disconnect the ignition coil.
2. Measure the resistance of the ignition coil windings.

• | The primary coil circuit resistance is between the first specified value.

• | The secondary coil circuit resistance is between the second specified value.

Was the resistance of both ignition coil circuits within the specified values?

0.36 to 0.55 ohms at -10 to 50°C (14 to 104°F)9.0k to 15.4k ohms at -10 to 50°C (14 to 104°F)

Go to Step 16

Go to Step 17

16

1. Check the distributor cap and the rotor for the following conditions:

• | Cracks

• | Corrosion on terminals

• | Carbon tracking

• | Water intrusion

2. Replace the distributor cap or the rotor as necessary.

Was a repair necessary?

--

Go to Step 20

Go to Step 17

17 | Replace the ignition coil. Refer to Ignition Coil Replacement in Engine Controls. Is the action complete? | -- | Go to Step 20 | --

18

1. Check for any of the following engine mechanical conditions:

• | Worn or faulty camshaft

• | Leaking or sticking valves

• | Leaking or sticking piston rings

• | Excessive valve deposits

• | Collapsed or sticking lifters

• | Weak valve springs

• | Incorrect valve timing

• | Leaking head gasket

2. Repair as necessary. Refer to Engine Compression Test in Engine Mechanical.

Was a basic engine mechanical problem found and repaired?

--

Go to Step 20

Go to Diagnostic Aids

19 | Replace any faulty spark plug wires. Is the action complete? | -- | Go to Step 20 | --

20

1. Perform the scan tool Clear DTC Information function.
2. Attempt to start the engine.

Does the engine start and continue to run?

--

Go to Step 21

--

21

1. Start the engine.
2. Run the engine at idle until normal operating temperature is reached.
3. Check for DTCs with a scan tool.

Are any DTCs displayed?

--

System OK

Go to the applicable Diagnostic table