How To Test The Ignition System (1995-1997 2.7L Honda Accord)

In this tutorial, I'll explain how to test the ignition system and find out if it's causing a no-start problem or a cylinder misfire problem.

All of the test steps are explained in a step-by-step manner and in plain English.

You'll be able to easily find out if the igniter (ignition control module), the ignition coil, the distributor cap and rotor, or the spark plug wires are behind a no-start problem or a cylinder misfire.

You can find this tutorial in Spanish here: Cómo Probar El Sistema De Encendido (1995-1997 2.7L Honda Accord) (at: autotecnico-online.com).

APPLIES TO: This tutorial applies to the following vehicles:

• 2.7L V6 Honda Accord: 1995, 1996, 1997.

WIRING DIAGRAM: You can find the ignition system wiring diagram here: Ignition System Wiring Diagram (1995-1997 2.7L Honda Accord).

Symptoms Of An Ignition System Problem

Ignition system problems will generally cause one of two problems:

• The engine will not start due to a lack of spark to all 6 cylinders.
• The engine starts, but runs with a cylinder misfire.

If the engine is misfiring due to an ignition system problem, you'll see one or more of the following trouble codes:

• P0300, P0301, P0302, P0303, P0304, P0305, P0306.

You're also gonna' see one or more of the following:

• The check engine light (CEL) will be illuminated on your instrument cluster.
• Your car will idle rough.
• A 'rotten egg' smell may come out of the tailpipe when you drive your car (or mini-van).
• Really bad gas mileage.
• Your vehicle does not pass the emissions test.

What Tools Do I Need To Test The Ignition System?

You don't need any expensive tools to test your Honda ignition system. Here's what you'll need:

1. A digital multimeter.
   • It doesn't have to be an expensive one, a cheapie one will do just fine.
2. A 12 Volt test light.
3. An LED light
   • I've included a link on what this LED light looks like and how to make it into a tool here: The LED Light Test Tool And How To Make One.
4. A wire piercing probe.
   • To see what this tool looks like, click here: Wire Piercing Probe.
5. An HEI spark tester.
   • This inexpensive spark tester is a MUST have tool to be able to correctly diagnose your Honda vehicle with the info/tests in this article.
   • If you want to learn how the HEI spark tester works, click here: The HEI Spark Tester (The Best Spark Tester On The Market).
6. A helper to crank the engine.

And lest I forget, a scan tool is not necessary to diagnose and test the Honda distributor type ignition system. All of the testing that you'll be doing will be done without an automotive diagnostic scanner.

How Does The Igniter (Ignition Control Module) Work?

In a nutshell and when the ignition system is working properly, this is what happens when you turn the key to crank and start your Honda:

1. 12 Volts are fed first to the ignition coil (when you turn the key to ON and then crank the engine), and from the coil to the igniter (ignition control module) inside of the distributor.
2. The engine starts to turn, which induces the 3 different crankshaft position sensors to start producing and sending their position signals to the fuel injection computer.
3. Upon receiving these position signals, the fuel injection computer sends a Triggering signal to activate the igniter.
4. The igniter upon receiving this Triggering signal in turn sends a Switching signal to the ignition coil.
5. The ignition coil, upon receiving this Switching signal, starts to spark away!
   • The Switching signal is just the 'switching' ON and OFF of the primary current flowing thru' the coil by interrupting its path to Ground.
   • The primary current is just the name for the 12 Volts that the ignition coil receives.
6. The fuel injection computer controls the igniter at start up and at all engine speeds after engine start up, unlike the majority of distributor-type ignition systems where the ignition control module freelances at engine start up.

Important Do's And Don'ts

Here are a few suggestions to help you to diagnose your Honda's ignition system free of headaches and/or complications:

1. Do not use a regular spark plug instead of a spark tester to test for spark.
2. Do not remove the spark plug wire from the spark plug while the engine is cranking to test for spark.
3. Keep your hands and fingers away from the rotating distributor shaft when your helper is cranking the engine during the tests.
4. Start your diagnostic from TEST 1, do not skip around from test to test.
5. Once again, use the recommended/indicated tools for all of your tests.

TEST 1: Testing For Spark At The Spark Plug Wires

To get your ignition system diagnostic on the road, I'm going to ask you to test all 6 spark plugs wires for spark.

It's important that you use a spark tester for your spark tests. Any other method of testing for spark, that does not involve a spark tester, may give you a false test result.

This false test result will have you chasing ghosts and replacing parts that won't solve the problem.

These are the test steps:

1. 1

   Remove the #1 cylinder spark plug wire from its spark plug.

2. 2

   Attach the HEI spark tester (or an equivalent spark tester) to the spark plug wire. See the photo above.

3. 3

   Connect the spark tester to the battery negative (-) terminal with a jump start cable.

4. 4

   Have your helper crank the engine while you observe the spark tester.

5. 5

   The spark tester will do one of two things:
   
   1.) Spark.
   
   2.) Not spark.

6. 6

   Repeat the test on all of the remaining spark plug wires.

Let's take a look at what your test results mean:

CASE 1: You got spark on all of the spark plug wires. This is the correct and expected test result.

It confirms that the ignition coil and the igniter (ignition control module) are working. If your Honda Accord is suffering a no-start condition, then this result indicates that the ignition system is not the cause of it.

CASE 2: You got NO spark from all of the spark plug wires. This lack of spark will definitely keep the engine from starting.

The next step is to check the ignition coil's high tension wire for spark. For this test go to: TEST 3: Testing For Spark At The Ignition Coil's High Tension Wire.

CASE 3: You got spark from some but not all of the spark plug wires. This test result tells you that the ignition system is behind a cylinder misfire.

The next step is to check for spark directly on the distributor cap towers of the spark plug wires that did not spark. Go to: TEST 2: Testing For Spark At The Distributor Cap.