There's a way to test just about anything under the hood. These tests can be done with VERY INEXPENSIVE testing equipment/tools. Hopefully this article has shed some light on just how easy it is to test these Coil-On-Plug ignition coils (with two wires in the connector) with some very basic tools.
In summarizing the key points of this entire article (of testing a Coil-On-Plug system), they are:
- Test for spark first, test for power second, test for the Switching signal third.
- The spark is done with an HEI spark tester for true results.
- A test light or multimeter can be used for the power test.
- An LED light can be used to test for the Switching signal.
- That these tests are easy.
- No scan tool is required.
- That knowing working theory will help you diagnose a Coil-On-Plug ignition coil (with two wires in the connector) of any make and model with such a Direct Ignition System.
These very simple tests have made the difference (for me) between successfully diagnosing the no-start or misfire condition and making a paycheck or not. They will help you too. After all, I have been using these testing tips and techniques everyday for years.
Testing ignition systems, whether they're distributor based, or Direct Ignition (coil pack or Coil-On-Plug types), all follow pretty much the same rules and their testing methods are also pretty much the same.
To see this, I recommend reading the two case studies in this tutorial that go into detail about this. They are:
- Carbon Tracks Are A Common Cause Of Ignition Misfires. This Neon uses a Direct Ignition System that is the coil pack type.
- 1988 Volvo 740 NO-START Case Study. This Volvo uses a distributor type conventional ignition system.
These other articles are worth exploring:
- No Start Testing And Diagnostic Basics
- Automotive Diagnostic Tips And Techniques: The Ignition Coil
- Ignition Coil Pack Testing Tips And Techniques
If this info saved the day, buy me a beer!
