So your Mazda Miata won't start when you turn the key. Before you storm off in a fit of frustration, perform a few quick troubleshooting steps. By doing so, you may learn a thing or two about engines and save yourself a healthy tow and repair bill. The majority of times, when a car won't start, the battery is the culprit. Don't give up the ghost until you take the time to go over some simple and basic checks. Who knows, you may just get to your appointment on time.
Turn the ignition key and listen for any clicking or machine gun-like noises from under the hood. If you hear these noises, turn the ignition key to the "Accessories" position then try turning on the Miata's radio, headlights or other electrical devices. If there is no action or lights when these are turned on, your battery is most likely dead and requires a jump start. If there are dim lights or trickle charges in the radio, with dial illumination or static reception, open the hood.
Prop the hood open and connect the red lead wire from the voltmeter to the red terminal on the Miata's battery. Connect the black lead wire from the voltmeter to the black terminal on the Miata's battery. Take a reading for voltage on the voltmeter. Check the Miata's battery volt recommendations and specifications on the battery's sticker. Compare the two numbers. If the reading is 4 volts or less than the battery's recommended operating range, the battery needs to be replaced or recharged. If you replace the battery, get the alternator tested as well as this may indicate a problem with the alternator.
Turn the key in the ignition and listen again if the fixes in Step 1 and 2 did not resolve the problem. Listen for the engine turning over but conking out quickly. Listen for any sputtering or jumpiness in the engine firing. If present, the car is very low or out of gas.
Open the hood and prop it up. Unscrew the carburetor cap and apply carb spray directly onto the interior of the cap housing. Close the cap, screw it down and try starting the car again. If the car starts, you need to get the fuel and air filter changed. It wouldn't hurt to replace the spark plugs at this point as well.
