Engine Cranks But Does Not Run

Engine Cranks but Does Not Run

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Initial Inspection and Diagnostic Overview
* Review Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions provides an overview of each diagnostic category.

Circuit/System 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.

Diagnostic Aids

If the cause of an engine cranks but will not run condition has not been found, inspect for the following conditions:

* Hard starting only in cold ambient temperatures. These may cause an intermittent condition that may not occur in the service bay:

- Fuel heater inoperative-Refer to Fuel Heater Inoperative. Fuel Heater Inoperative
- Ice blockage at the fuel pickup in the fuel tank-This will be a high vacuum in the supply lines while cranking, and the problem will disappear after the vehicle is brought in the service bay. It may also exhibit a start and stall condition or a starting condition with no acceleration.

* The correct cranking speed is 100 RPM cold and 180 RPM hot.
* A basic engine problem
* Low engine coolant may cause the engine to shut down.

Special Tools

CH-48027 Vacuum Gage

Circuit/System Verification

Important: This diagnostic assumes the following:

* The batteries are completely charged. Refer to Battery Inspection/Test. Battery Inspection/Test

* The cranking speed is within specifications. Refer to Engine Cranks Slowly. Engine Cranks Slowly

* There is adequate fuel in the fuel tanks.

1. If DTCs P0090, P0191, P0193, P0335, P0336, P0340, P0602, P0603, P0604, P0606, P0642, P0643, P064C, P0698, P0699, P2510 are set diagnose those DTCs first.
2. The engine starts and runs.

^ If the engine does not start and run perform the Circuit/System Testing.

Circuit/System Testing

Important: You must perform the Circuit/System Verification before proceeding with Circuit/System Testing.

1. Inspect for the following conditions:

* Fuel smell or leak-Refer to Fuel Leak Diagnosis. Fuel Leak Diagnosis
* A plugged air filter collapsed air intake duct
* A restricted exhaust system-Refer to Symptoms - Exhaust System. Symptoms - Engine Exhaust
* Contaminants in fuel-Refer to Contaminants-in-Fuel Diagnosis. Contaminants-in-Fuel Diagnosis

2. Install the CH-48027 to the fuel rail service port and crank the engine.

^ If more than 5 inches Hg of vacuum was present during cranking, replace the fuel filter and inspect the fuel system restrictions.

3. Perform the Engine Compression Test. Refer to Engine Compression Test. Testing and Inspection

Important: During the replacement of the injectors, inspect the inlet and outlet fittings for corrosion or contamination. Refer to Contaminants-in-Fuel Diagnosis. Contaminants-in-Fuel Diagnosis

^ If any fuel vapor was emitted during the engine compression test, replace the affected fuel injector.

4. Crank the engine for 15 seconds.

^ If the Actual Fuel Rail Pressure parameter is less than 10 MPa while cranking the engine, refer to Fuel System Diagnosis. Component Tests and General Diagnostics

Repair Instructions

Fuel Injector Replacement (Left) Fuel Injector Replacement (Right)

Repair Verification

The engine starts and runs.