• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
• | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
• | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
This Engine Cranks but Does Not Run is an organized approach to identify a condition which causes the engine to crank but not start. This diagnostic directs the technician to the appropriate system diagnosis.
This diagnostic assumes the system voltage levels are adequate for starter motor operation. Refer to Battery Inspection/Test , and Engine Cranks Slowly . Fuel level and fuel quality should be determined for correct diagnosis.
Control Module References for scan tool information
• | CH-48027 Digital Pressure Gage |
• | J 26792 HEI Spark Tester |
Attempt to start the engine. The engine should start and run.
⇒ | If any of the following DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle to diagnose those DTCs P0201-P0208, P0230, P0335, P0336, P0340, P0403, P0404, P0601, P0602, P0603, P0604, P0606, P0607, P060D, P062F, P0641, P0651, P0685, P0689, P0690, P1516, P2610. |
⇒ | If the reading is not correct for your altitude, diagnose the MAP sensor. Refer to DTC P0106 . |
⇒ | If spark is not observed refer to Electronic Ignition (EI) System Diagnosis . |
Important: Additional DTCs may set when using the fuel pump output control.
⇒ | If the fuel pump does not respond refer to Fuel System Diagnosis . |
⇒ | If the fuel pressure is not within 384-425 kPa (55-61 psi), refer to Fuel System Diagnosis . |
• | Compare the actual engine coolant temperature to the ECT parameter. |
• | Air filter and air intake system for restrictions and obstructions |
• | Test the fuel for contamination. Refer to Alcohol/Contaminants-in-Fuel Diagnosis . |
• | Inspect the spark plugs. Refer to Spark Plug Inspection . |
• | Test the exhaust system for restrictions. Refer to Restricted Exhaust . |
• | Engine mechanical conditions such as worn timing chain gears, low compression, etc.--Refer to Engine Compression Test . |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.