Car Engine Starts But Won’t Stay Running

Causes

• Fuel system problems
• Ignition system problems
• Air induction system problems
• Electrical system problems
• Mechanical problems

Fuel System Problems

Fuel system problems can cause the engine to start but not stay running if the fuel is not getting to the engine or if the fuel is not being mixed properly with air.

• Clogged fuel filter
• Faulty fuel pump
• Leaking fuel lines
• Dirty fuel injectors
• Faulty fuel pressure regulator

Ignition System Problems

Ignition system problems can cause the engine to start but not stay running if the spark plugs are not firing or if the ignition timing is incorrect.

• Faulty spark plugs
• Faulty spark plug wires
• Faulty ignition coil
• Faulty ignition module
• Incorrect ignition timing

Air Induction System Problems

Air induction system problems can cause the engine to start but not stay running if the engine is not getting enough air or if the air is not being mixed properly with fuel.

• Clogged air filter
• Faulty mass air flow sensor
• Leaking vacuum hoses
• Faulty throttle position sensor
• Faulty intake manifold gasket

Electrical System Problems

Electrical system problems can cause the engine to start but not stay running if the battery is not providing enough power or if the electrical connections are faulty.

• Weak battery
• Faulty alternator
• Faulty starter
• Loose or corroded electrical connections
• Faulty ignition switch

Mechanical Problems

Mechanical problems can cause the engine to start but not stay running if the engine is not able to run properly.

• Worn piston rings
• Faulty valves
• Faulty camshaft
• Faulty crankshaft
• Overheated engine

Diagnosis

To diagnose the cause of why your car engine starts but won’t stay running, you will need to perform a series of tests.

1. Check the fuel system
2. Check the ignition system
3. Check the air induction system
4. Check the electrical system
5. Check for mechanical problems

Repair

Once you have diagnosed the cause of the problem, you can begin to repair it.

If the problem is with the fuel system, you may need to replace the fuel filter, fuel pump, or fuel injectors.

If the problem is with the ignition system, you may need to replace the spark plugs, spark plug wires, ignition coil, or ignition module.

If the problem is with the air induction system, you may need to replace the air filter, mass air flow sensor, or throttle position sensor.

If the problem is with the electrical system, you may need to replace the battery, alternator, starter, or ignition switch.

If the problem is with the mechanical system, you may need to rebuild the engine.

Prevention

There are a few things you can do to prevent your car engine from starting but not staying running.

• Keep up with regular maintenance
• Use high-quality parts
• Avoid driving in extreme conditions
• Have your car inspected by a qualified mechanic