You'll also know for sure if what you have is a bad coil or if you need to spend money on further troubleshooting. The HEI test plug will put a heavy load on the coil. The Power and Ground Circuits of the Coil-On-Plug ignition coil (type with three wires in the connector) have to be tested to find out the real reason you got a No spark result on your spark tester. Repair the open-circuit problem and retest for spark or retry starting the vehicle. Ign coil secondary resistance 6,000 - 9,000 ohms . Only a dedicated spark tester will stress test the Coil on Plug ignition coil. The coil is the engine component that creates the voltage to fire the plug, and if it's damaged and can't do its job, you may have to replace it. Although testing ignition coils can be tricky, it’s doable if you have the tools and knowledge. Put the securing screws aside. You'll have to consult your repair manual's wiring diagrams to make sure how everything is wired up. So whether it's a Ford, a Chevrolet, a Mazda, a Suzuki, a Mitsubishi or whatever in the USA, or Europe or South or Central America, or where ever on the planet, these easy tests work. Here are the possible results: The Ground Circuit is tested with the Key On or Off. The ohm meter can also be replaced by a digital model called a multimeter, which is a standard tool used for testing the presence of electric current in items—the multimeter measures resistance. A weak or damaged ignition coil can cause engine misfires, stalling, and lower fuel economy. Measuring ignition coil resistance was once a popular test method. Pull the plug wire out of the coil where it inserts: It's typically just pushed-in onto a spike in the coil. You must then disconnect the coil from the distributor wire. If it is even a little out of spec, the coil should be replaced. By using this method, both the primary and the secondary windings can be tested. You may get a reading between 5000 to 15000 ohms, depending on your particular model. IMPORTANT: Before you start, read the following first:TIP 1: The very first thing you have to do, before you start testing with the info in this article, is to find out which cylinder or cylinders are misfiring. To test the resistance of the coil in your chainsaw which is called a bench test, take your multimeter and remove the coil from your chainsaw to get easy access to its electrical terminals. When testing ignition coils, it is possible to have some spark; however, the spark may not be sufficient to fire the spark plugs under compression conditions. When testing the condition of the secondary winding, the terminals of the multimeter should be placed on one of the outer posts as well as the center post where the coil wire attaches. Testing the ignition coils on your 3.5L 5 cylinder or 4.2L 6 cylinder is not that hard to do and I'll show you how to do it in this tutorial. The Ground Circuit is tested with the Key On or Off. Take the good unit, or a new coil and reconnect it to the engine bracket. As an Amazon Associate, I may earn a small commission from qualifying purchases from the Amazon product links from this website. I assume the ignition module is bad. Required fields are marked * Guided test: Coil-on-plug (4-wire) - trigger and feedback - voltage. The fuse or relay that supplies this voltage is blown or bad. A multimeter is one of the best tools for testing and diagnosing a plug socket. I'm gonna' explain both in this article. While ignition coils will generally last for the life of a vehicle, faulty spark plugs or spark plug wires can send irregular voltage surges through the ignition coil, causing the coil to burn out. Place one end of your multimeter or test light on the battery positive terminal and with the other end, probe the Ground Circuit. Testing the ignition coils on your 3.5L 5 cylinder or 4.2L 6 cylinder is not that hard to do and I'll show you how to do it in this tutorial. The most likely cause will be an open-circuit problem in that ignition coil's Power Circuit. Your purchase helps support my work in bringing you real diagnostic testing information to help you solve the problem on your vehicle. When testing a coil-on-plug (COP) ignition system, one of the first steps is to understand the system operation. In this example, 3.5 = 3500. An ignition coil is made up of the primary and the secondary wire windings. Open your hood and unplug all four wire pin connectors on the coil pack. A typical coil-on-plug (COP) ignition coil . And it's just that the Coil-On-Plug ignition coil is bad. I recommend the following article to learn more about carbon tracks Ignition Misfire a Case Study of a Dodge Neon. Your email address will not be published. In this step-by-step guide, we will go over how to test whether an ignition coil is good or bad by examining the resistance using a digital multimeter. If the coil in your car is defective, you can get a new coil at most auto parts stores or the dealer. Wikibuy Review: A Free Tool That Saves You Time and Money, 15 Creative Ways to Save Money That Actually Work. At this time, you can use a screwdriver and put it near the armature then energize the solenoids. GM  |   Note: We will not be covering distributor-style ignition systems that use just one coil. Please check out my other vids and subscribe. Do NOT follow this link or you will be banned from the site! When an engine with coil-on-plug (COP) ignition starts to misfire, there are two challenges: finding out which cylinder is misfiring and finding out why. Then start the engine and watch the tester window. That method will only tell if there is something seriously wrong with the coil (aka if it's dead). secondary winding resistance is the plug leads test there should be 20-30K for spec. By testing your disconnected ignition coil first, using a multimeter, you'll be using data and numbers to determine the health of the coil rather than relying on your eyeballs. Red is power, Black is Earth. A carbon track on the coil's boot or on the spark plug may be diverting the spark. If you want to find out more about how this tool works, I recommend the following article (within this site): The HEI Spark Tester (The Best Spark Tester On The Market).. You'll get one of two results with the spark test. Replacing the ignition coil with a new one will only be a waste of time and money since, without Power the new one will not spark. Testing the ignition coil and the spark plug Connect the tester between the spark plug boot and the spark plug. This spark tester isn't expensive and more importantly can be bought just about anywhere (online, auto parts stores, mechanic tool trucks, etc.) One of the coil’s terminals should be shown leading to the spark plug. The coils then convert the energy to a higher voltage, of atleast 50,000 volts, in order to create a spark. Turn on your meter and touch the spark plug wire terminals on one of the coils with the meter leads. This checks the secondary resistance. You can unplug the injector for the cyl you're testing if you want. Since the power circuit is shared by all of the coils on the majority of Coil-On-Plug ignition systems. Let's continue and find out about testing the other signals that the Coil on Plug ignition coil needs to create spark. This same test (either side of primary to ground) on a known good module (Jonsey 2050) reads 215 ohms. VW  |   After replacing the blown fuse or the defective relay. In this video learn how to check resistance using a multimeter. Name * Email * Website. Help us improve our tests . Testing your ignition coil by using a multimeter After you have ensured the spark plug is not an issue, it’s time to check on the ignition coil. You can test a 12-volt ignition coil for effectiveness by checking the resistance of its wire windings with a multimeter. Step 5: Test the secondary circuit of the ignition coil. By using a multimeter, the coils can be checked against a known number and any difference will be clearly shown. As you can see in the photo above, testing for spark is achieved by using a spark tester. Most people think you can check a small engine's ignition system by removing the spark plug and grounding it while cranking the engine and watching for a spark. While the first method is a basic go or no-go test, it does not indicate the condition of the coil, whereas the second test does. Isuzu  |   The HEI Spark Tester (The Best Spark Tester On The Market). You can get them at any parts store. Turn off the Power. 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