Reasons why your car engine will turn but not start
1. Sensor failure – The engine control module (ECM) uses data from various sensors to control engine functions. Problems with a sensor failure such as the crankshaft position sensor or camshaft position sensor can cause your car to not start.
2. Ignition system issues – A weak or defective ignition coil can cause your car to not start. Additionally, worn spark plugs or wires can also cause the engine to not start.
3. Fuses and Relays – Check the fuse box for blown fuses and faulty relays related to the ignition and fuel systems. Identification diagrams can usually be found in the fuse box or in the owner’s manual. Replace any blown fuses or faulty relays to see if that fixes the problem.
4. Anti-theft system activated – If the security system is accidentally activated, your car may not start even if it is started. Consult your vehicle’s owner’s manual (or the owner’s manual for an upgraded alarm system) to learn how to reset or disable the system.
5. Transponder key problem – Transponder keys contain a chip that sends a signal to your car’s immobilizer. You may need to replace or reprogram the key.
Troubleshooting Tips
1. If the engine starts but does not start, turn off the car and remove the intake tube attached to the throttle body. Then, after carefully opening the throttle, spray a small amount of jump starter spray into the engine. Then try starting the engine again.
2. If the engine starts but dies after a few seconds, it means it’s out of fuel but spark and compression are fine. However, if the engine won’t start, you’ve almost certainly lost spark.
3. Do not crank your car’s engine repeatedly as this can wear out the starter motor or drain the battery.
4. If you have to try multiple times, wait a few minutes for the starter to cool after each 15 seconds. It should only take a few seconds per try to tell if the problem is fixed.
5. Modern cars have many different electrical components that can cause errors when starting the engine, so it is very important to check for problems with sensors and actuators.
6. Modern cars have many different electrical components that can cause failures, and the best thing to do is check the recorded error codes with a diagnostic tool. Purchasing an OBD2 diagnostic tool is a good investment (it doesn’t cost much).
For example, if the scan shows DTC P1682, there is an imbalance in the ignition circuit that may prevent the car from starting.