You will also want to check the vacuum hose to the fuel pressure regulator to make sure there are no leaks around it. Can Bad Spark Plugs Cause a Car To Crank But Not Start? While, bad or failing spark plugs can cause a number of problems. Another reason that spark plugs foul is that the fuel injector is clogged. Running lean means hotter operating temperatures which can cause an increased wear factor for your car spark plugs. Also, be sure to regap the spark plug electrode gap back to specifications (which requires a spark plug gapping tool or feeler gauge). Ignition problems can also cause wet spark plugs. Spark Plugs and Gasoline Fuels For gasoline fuels, the residuals of carbon compounds from rich mixtures of gasoline fuels can cause discoloration. Spark plugs usually fall into the first category, and that’s what this article is going to discuss: Using spark plug diagnosis to look for possible issues with your engine. If a spark plug gets gasoline in it, the significant problem is that the moisture created by the gasoline makes it impossible for the spark plug to generate sparks. Increasing the heat range slightly can improve fouling resistance by helping the plugs run hotter. Auto Parts stores sell spark plug cleaner devices that sand blast the end of the spark plug to remove deposits. Fuel system problems may cause a rich or lean condition, which can contribute to spark plug misfires. Leaky Head Gasket. This can be caused by a number of variables, such as engine flooding, or excessive moisture build up. A flooded engine is most typically caused by the driver excessively pressing on the gas before turning the ignition in the car. Proper gasoline fuel mixtures for long endurance racing usually leave only a faint porcelain discoloration. The recommended gap is usually specified on an underhood emissions decal in the engine compartment. Engine is Misfiring. Handling: Remove all the spark plugs, crank the starter motor to bring fresh air into the cylinder and make the air-fuel ratio leaner. All spark plugs wear out as they age, and at some point will cause spark plug problems. Ignition coils tend to fail because of bad spark plugs or plug wires. On 1996 and newer vehicles with OBD II, spark plug misfiring will usually turn on the Check Engine light and set one or more P030X misfire codes where "X" is the number of the cylinder that is misfiring. According to AA1Car.com, this occurs when the spark plug fails to fire, or fouls out. attempting to start a cold engine. In addition, the diluted fuel has a reduced octane rating that may cause your engine to “knock” due to predestination. If the spark plugs are old, worn, fouled, or damaged, they might not spark. The culprit for gas-soaked spark plugs is a flooded engine. The gasoline-and-air mixture will simply remain that, and the lack of ignition will deprive the car of any power to drive it. A spark plug is an electrical device that provides, as the name suggests, the sparks needed to ignite the gasoline in an engine, which in turn powers the vehicle. Cause: Clogged Fuel Injector. Normal spark plug deposits are typically light tan or brown in color. A bad fuel pressure regulator can also lead to poor acceleration. Carbon-fouled plug: Black, dry, fluffy soot on insulator tip and electrodes. This temporarily cuts off the fuel supply to the engine so it will pull in more air and hopefully help dry the wet spark plugs. Spark plugs are designed to be self-cleaning up to a point. The trade-off, however, may be an increased tendency to foul if the engine is idled too long or only driven at slow speed (as when driving around at a cruise night event). To check the vacuum hose to the fuel pump, fuel injection and systems. Will cause spark plug should be able to generate sparks again, returning to working order there make! 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