Car Engine Turns Over But Doesn’t Start

Introduction

When you turn the key in your car, you expect the engine to start. But what happens when the engine turns over but doesn’t start? This can be a frustrating and confusing problem, but it’s usually not difficult to fix.

Causes of a Car Engine Turning Over But Not Starting

There are several possible causes of a car engine turning over but not starting. Some of the most common causes include:

No spark. The spark plugs are responsible for creating the spark that ignites the air/fuel mixture in the cylinders. If the spark plugs are worn out or fouled, they may not be able to create a strong enough spark to ignite the mixture.
No fuel. The fuel pump is responsible for delivering fuel to the engine. If the fuel pump is not working properly, the engine will not be able to get the fuel it needs to run.
No air. The air filter is responsible for filtering the air that enters the engine. If the air filter is clogged, the engine will not be able to get the air it needs to run.
Compression problems. The engine’s compression is responsible for creating the pressure that is needed to ignite the air/fuel mixture. If the engine’s compression is too low, the mixture will not be able to ignite.
Electrical problems. The engine’s electrical system is responsible for providing power to the spark plugs, fuel pump, and other components. If there is a problem with the electrical system, the engine may not be able to get the power it needs to run.

Troubleshooting a Car Engine That Turns Over But Doesn’t Start

If your car engine is turning over but not starting, the first step is to troubleshoot the problem. Here are some steps you can follow:

Check for spark. Remove one of the spark plugs and hold it against the engine block. Have someone crank the engine while you watch for a spark. If there is no spark, the problem may be with the spark plugs, the ignition coil, or the ignition module.
Check for fuel. Disconnect the fuel line from the fuel injector rail and point it into a container. Have someone crank the engine while you watch for fuel to come out of the line. If there is no fuel, the problem may be with the fuel pump, the fuel filter, or the fuel injectors.
Check for air. Remove the air filter from the engine and inspect it for clogs. If the air filter is clogged, replace it with a new one.
Check for compression. Use a compression tester to check the compression in each of the engine’s cylinders. The compression should be between 100 and 150 psi in each cylinder.
Check for electrical problems. Use a voltmeter to check the voltage at the battery, the starter, and the ignition coil. The voltage should be between 12 and 14 volts at each of these points.

Fixing a Car Engine That Turns Over But Doesn’t Start

Once you have identified the cause of the problem, you can begin to fix it. Here are some tips for fixing a car engine that turns over but doesn’t start:

Replace the spark plugs. If the spark plugs are worn out or fouled, replace them with new ones.
Replace the ignition coil. If the ignition coil is not working properly, replace it with a new one.
Replace the ignition module. If the ignition module is not working properly, replace it with a new one.
Replace the fuel pump. If the fuel pump is not working properly, replace it with a new one.
Replace the fuel filter. If the fuel filter is clogged, replace it with a new one.
Replace the fuel injectors. If the fuel injectors are not working properly, replace them with new ones.
Fix the air filter. If the air filter is clogged, replace it with a new one.
Fix the compression problems. If the engine’s compression is too low, you may need to rebuild the engine.
Fix the electrical problems. If there is a problem with the engine’s electrical system, you may need to replace the battery, the starter, or the ignition coil.

Conclusion

If your car engine is turning over but not starting, don’t panic. There are a number of possible causes for this problem, and most of them are relatively easy to fix. By following the steps outlined in this article, you can troubleshoot the problem and get your car running again in no time.