Car Cranks But Won't Start: Fuel, Spark or Air?

No fuel getting to the engine

Likely causes

• Empty tank with a faulty fuel gauge
• Failed fuel pump, fuel pump relay or blown fuse
• Clogged fuel filter

What to check

1. Turn the key to ON and listen for a two-second hum from the fuel tank area. Silence suggests the pump, relay or fuse.
2. Find the fuel pump fuse and relay in your owner's manual and check them first. They are cheap and easy.
3. Only after that, look at the fuel filter and fuel pressure.

No spark: the tachometer does not move while cranking

Likely causes

• Failed crankshaft position sensor
• Failed camshaft position sensor
• Ignition coil or ignition module failure

What to check

1. Watch the tachometer while someone cranks. If the needle never moves, the computer is not seeing the engine turn, which points at the crankshaft position sensor.
2. Check for stored codes with a scan tool. Position sensor codes are common here.
3. Sensor failures often start when the engine is hot and works again after it cools, so note when it happens.

It cranks too easily or faster than normal

Likely causes

• Broken timing belt or chain on some engines
• Severe mechanical damage

What to check

1. A starter that spins noticeably faster than usual, with no struggle, can mean the engine is not building compression.
2. Stop cranking and have it checked. On some engines a broken timing belt can cause further damage if you keep trying.

The security light stays on or blinks while cranking

Likely causes

• Immobilizer not recognizing the key
• Dead battery in the key fob (on push-button cars)

What to check

1. Try your spare key.
2. On push-button cars, hold the fob against the start button as the manual describes and try again.

Related guides

• Car Won't Start: What to Check Based on What You Hear
• Clicking Noise When Starting: Battery, Starter or Engine?
• P0606: ECM/PCM Processor Fault