What to Do When Your Car Will Not Start
Every engine requires four basic ingredients to start: sufficient cranking speed, good compression, adequate ignition voltage (with correct timing) and fuel (a relatively rich air/fuel mixture initially). So if your car fails to start, you can assume it lacks one of these four essential ingredients. But which one?
To find you, you need to analyze the situation. If the engine won't crank, you are probably dealing with a starter or battery problem. Has the starter been acting up? (unusual noises, slow cranking, etc.). Is this the first time the engine has failed to crank or start, or has it happened before? Have the starter, battery or battery cables been replaced recently? Might be a defective part. Has the battery been running down? Might be a charging problem. Have there been any other electrical problems? The answers to these questions should shed some light on what might be causing the problem.
If an engine cranks but refuses to start, it lacks ignition, fuel or compression. Was it running fine but quit suddenly? The most likely causes here would be a failed fuel pump, ignition module or broken overhead cam timing belt. Has the engine been getting progressively harder to start? If yes, consider the engine's maintenance and repair history.
There is a big difference between “won't start”, and “won't crank or turn over”. No crank is when you turn the key or hit the start button and no sound is heard but maybe a click. Won't start means the starter is turning the engine over, but the engine won't catch or fire. The service personnel need to know which problem you have so the technician isn't wasting time, (and your money) looking for the wrong problem. No crank issues are generally related to the battery, electrical connections, security issues, starter relays, starter, ect. No start issues are generally related to lack of fuel to the engine, power train control problems such as ignition or injector problems, stuck open EGR valves, plugged exhaust etc.