Crank the Ignition and Inspect for Spark Have someone turn the ignition so that you can inspect the plug. Make sure the spark is strong and blue in color. If the spark is weak and dull orange, it's likely that it's not strong enough to ignite the engine's air and fuel mixture.
The most common signs of bad spark plugs include start-up trouble, rough idling, sluggish acceleration, declining fuel economy, engine misfiring, and engine knocking.
A good spark will be blue-white and will be plainly visible in daylight. If a good spark is present, the problem is probably not in the ignition system. Check the fuel system and/or stark timing. Weak sparks are orange or red and may be hard to see in daylight.
Test with a spark plug tester
Turn the ignition ON. Start the engine, or simply turn it over if it won't start, and watch the transparent sides of the tester. If no visible spark or glow is present, then you can be sure that no spark is occurring at the all-important tip of the spark plug.
A spark-ignition engine is an internal combustion engine, generally a petrol engine, where the combustion process of the air-fuel mixture is ignited by y a spark from a spark plug. A bright blue spark is best. A yellow/orange spark signifies weak ignition. The hottest spark is ultraviolet which we can't see.
If the firing end of a spark plug is brown or light gray, the condition can be judged to be good and the spark plug is functioning optimally.
Loss of spark is caused by anything that prevents coil voltage from jumping the electrode gap at the end of the spark plug. This includes worn, fouled or damaged spark plugs, bad plug wires or a cracked distributor cap.
To test if your installation was successful, open Command Prompt, change to SPARK_HOME directory and type bin\pyspark. This should start the PySpark shell which can be used to interactively work with Spark. The last message provides a hint on how to work with Spark in the PySpark shell using the sc or sqlContext names.
The spark on the tester should be a bluish-white color; an orange or red color indicates a weak spark. If you have a weak spark, you may be dealing with a: bad spark plug wire.
The strength of the spark is revealed in the color. A red or yellow spark is weak and probably will not spark in the cylinder. A blue or white spark is strong and has enough voltage to fight across the spark plug gap even under pressure within the cylinder.
Should I feel a spark immediately? No! An immediate spark can actually mean very little in the grand scheme of a relationship. In fact, sometimes a spark right off the bat can actually be "dangerous" or even a red flag, according to Hinge's Director of Relationship Science, Logan Ury, author of How to Not Die Alone.
Ordinary copper and nickel spark plugs should be changed every 30,000 to 50,000 miles, unless otherwise suggested by the spark plug manufacturer. Platinum and iridium spark plugs tend to last longer than standard copper and nickel spark plugs. Expect to change them every 60,000 to 150,000 miles unless otherwise noted.
The general rule of thumb about how often to change spark plugs is that they should be replaced after about 100,000 miles of driving.
A misfire feels like your engine suddenly loses power. You might experience a hesitation when you try to accelerate the vehicle. If it feels like your vehicle is accelerating slower than usual or if it feels rough, the cause could be an engine misfire.
The proper method to check for spark is with a spark tester. It resembles a spark plug but has a sunken center electrode that simulates a load on the coil. Holding the plug wire and seeing if a spark jumps to ground is inconclusive. The spark is arcing in atmospheric pressure.
If the spark is weak and you try to run the engine fast, the combustion gases inside the cylinder will actually blow out the spark. Then, instead of an explosion, you get nothing. And when you're getting nothing from some of your cylinders some of the time, the engine will sputter, cough and lurch.
The Car Has Trouble Starting
If spark plugs have become clogged or worn down, the car's engine has to work overtime in order to make up for the overworked plugs. Sometimes the car will not start at all because there is simply not enough spark created to turn the engine over.
Make sure the spark is strong and blue in color. If the spark is weak and dull orange, it's likely that it's not strong enough to ignite the engine's air and fuel mixture.
Tighten the spark plug finger-tight until the gasket reaches the cylinder head, then tighten about ½ – ⅔ turn more with a spark plug wrench.