Fuel Delivery System:
* Empty Fuel Filter: A clogged fuel filter restricts fuel flow to the engine. This is a relatively inexpensive and easy part to replace.
* Fuel Pump Failure: The fuel pump might be malfunctioning, unable to push fuel from the tank to the engine. This is a common cause of no-start issues. Symptoms might include a whining sound from the fuel tank area when the key is turned on (though not always).
* Bad Fuel Pump Relay: The relay acts as a switch for the fuel pump. A faulty relay prevents the pump from receiving power.
* Clogged Fuel Injectors: If the injectors are clogged, fuel can't reach the engine's cylinders. This often leads to rough running or poor starting *if* the engine manages to start at all, but a complete blockage can prevent starting.
* Fuel Pressure Regulator: This regulates the fuel pressure in the fuel rail. A faulty regulator can cause low or erratic fuel pressure.
* Leaking Fuel Line: A hole or crack in the fuel line will prevent fuel from reaching the engine. Check all visible lines for damage.
Ignition System:
* Bad Spark Plugs or Wires: Worn-out spark plugs or damaged wires will prevent a spark, which is needed for combustion.
* Ignition Coil Failure: The coil provides the high voltage for the spark plugs. A failing coil can lead to misfires or no start at all.
* Crankshaft Position Sensor (CKP Sensor): This sensor tells the computer the engine's rotation. A faulty sensor will prevent the engine from starting.
* Cam Position Sensor (CMP Sensor): Similar to the CKP sensor, a bad CMP sensor will prevent proper engine timing and starting.
* Ignition Switch: A faulty ignition switch might not be providing power to the rest of the system.
Other Possibilities:
* Security System Issues: Some anti-theft systems can prevent the engine from starting if the key isn't recognized. Check your owner's manual.
* Low Battery: A weak battery might not provide enough power to crank the engine over. Check the battery voltage.
* Starter Motor: A bad starter won't crank the engine, preventing it from starting. You should hear a clicking sound when you turn the key if this is the problem.
* Fuses and Relays: Check the fuses and relays related to the fuel system and ignition system.
Troubleshooting Steps:
1. Check the obvious: Make sure the car is in park (automatic) or neutral (manual).
2. Listen for the fuel pump: Turn the key to the "on" position (don't crank the engine). You should hear a brief whirring sound from the fuel tank area. If not, the pump might be dead or the relay is faulty.
3. Check the battery: Test the battery voltage with a multimeter.
4. Inspect visible fuel lines: Look for leaks or damage.
5. Check fuses and relays.
If you're not comfortable performing these checks yourself, take your Malibu to a qualified mechanic for diagnosis and repair. Trying to diagnose complex fuel or ignition problems without the right tools and knowledge can be dangerous and might lead to further damage.
