Testing The Ignition Coils -Misfire Condition (1998, 1999, 2000, 2001 2.5L Ford Ranger And Mazda B2500)

This tutorial will help you to test the ignition coil packs and see if they are causing a misfire condition on the 1998, 1999, 2000, 2001 2.5L Ford Ranger (Mazda B2500).

This tutorial only focuses on testing a misfire condition caused by the ignition coil packs or the spark plug wires.

NOTE: You can find the ignition system wiring diagram here: Ignition System Circuit Diagram (1998-2001 2.5L Ford Ranger).

Ignition Coil Basics

Testing The Ignition Coils -Misfire Condition (1998, 1999, 2000, 2001 2.5L Ford Ranger And Mazda B2500)

The 2.5L Ford Ranger (Mazda B2500) comes equipped with 2 ignition coil packs. The engine itself has 8 spark plugs. Four of those spark plugs are on the exhaust manifold side. The other 4 are on the intake manifold side.

The spark plugs on the exhaust manifold side get spark from the primary ignition coil pack. The spark plugs on the intake manifold side get spark from the secondary ignition coil pack.

The most important thing that you need to know, about this type of ignition system, is that each coil pack is made up of two individual ignition coils.

Each of those individual ignition coils fire spark simultaneously to 2 cylinders. The cylinders that get spark simultaneously are cylinders #1 & #4 and #2 & #3.

In 8 out of 10 cases, when one of the ignition coil packs fails on your 2.5L Ford Ranger, the coil pack will stop transmitting spark from two of its towers. These two towers usually belong to the same individual coil that feeds spark to 2 cylinders simultaneously.

Ignition Coil Testing Basics

I can tell you from personal experience that testing the ignition coil packs on the 2.5L Ford Ranger isn't difficult.

The one thing that's going to help you to avoid complications is using a dedicated spark tester to test for spark.

There's one specific spark tester that I use and that I recommend for you to use. This bad boy is the HEI spark tester. You can find out more about it here: The HEI Spark Tester (The Best Spark Tester On the Market) and you can buy it here: OTC 6589 Electronic Ignition Spark Tester.

Another important suggestion I'd like to share with you is that all 8 spark plug wires should be tested for spark even if you have a specific misfire trouble code pinpointing a specific cylinder as dead.

The way that I have designed this tutorial, you'll start off by testing the secondary ignition coil pack (starting point is TEST 1) and if it tests good, then you'll go on to test the primary ignition coil pack (starting point is TEST 3).

TEST 1: Checking For Spark (Exhaust Side)

Testing The Ignition Coils -Misfire Condition (1998, 1999, 2000, 2001 2.5L Ford Ranger And Mazda B2500)

In this test section we're gonna' check that the 4 exhaust manifold side spark plug wires are sparking when the engine runs.

The ignition coil that feeds spark to these exhaust manifold signed spark plug wires is the primary ignition coil pack.

NOTE: Even if you have a specific misfire trouble code identifying a specific cylinder as misfiring, it's important to test all 4 spark plug wires on your 2.5L Ford Ranger (Mazda B2500).

IMPORTANT: To get the most accurate test result, you should use a dedicated spark tester. The spark tester that I recommend that you use is the: OTC 6589 Electronic Ignition Spark Tester.

Let's get started:

  1. 1

    Disconnect the spark plug wire from the #1 cylinder spark plug.

  2. 2

    Connect the spark tester to the spark plug wire.

    Ground the spark tester with a jump start cable to the battery negative (-) terminal of your Ford Ranger.

  3. 3

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

  4. 4

    The spark tester should spark the entire time the engine is running.

  5. 5

    Repeat the spark test on the remaining exhaust side spark plug wires.

Let's examine your spark test results:

CASE 1: All of the exhaust side spark plug wires sparked. This is the correct test result and lets you know that the primary ignition coil is working correctly. You can also conclude that the spark plug wires are not defective.

Your next step is to check that all of the secondary ignition coil spark plug wires are sparking. For this test go to: TEST 3: Checking For Spark (Intake Side).

CASE 2: One of the exhaust side spark plug wires DID NOT spark. The next step is to check for spark directly on the ignition coil tower that connects to this non-sparking spark plug wire.

For this test go to: TEST 2: Primary Ignition Coil Tower Spark Test.

CASE 3: Two exhaust side spark plug wires that connect to two ‘paired’ cylinders DID NOT spark (paired cylinders are: #1 & #4 and #2 & #3). This usually indicates that the exhaust side ignition coil is defective.

But to be sure, the next step is to check for spark directly on the ignition coil towers that connect to these two non-sparking spark plug wires. Go to: TEST 4: Primary Ignition Coil Tower Spark Tests (Paired Cylinders).