This tutorial will help you diagnose a bad ignition coil that's causing your 2.4L Nissan D21 pickup from starting.
Everything is explained in plain English and in a step-by-step manner so that you can find out if the ignition coil is defective or not.
Contents of this tutorial at a quick glance:
- Ignition Coil Circuit Descriptions.
- Making Sure Spark Is Missing At All Spark Plug Wires.
- TEST 1: Testing For Spark Directly On The Ignition Coil Tower.
- TEST 2: Making Sure The Ignition Coil Is Getting Power.
- TEST 3: Making Sure The Power Transistor Is Activating The Ignition Coil.
- Where To Buy The Ignition Coil.
The following tutorials complement this one:
- How To Test The Power Transistor 1992-1994 Nissan D21 Pickup.
- 1992-1994 2.4L Nissan D21 Pickup Ignition System Wiring Diagram.
Ignition Coil Circuit Descriptions
The ignition coil, on the 1992, 1993, and 1994 2.4L Nissan D21 Pickup has 2 wires coming out of its engine wiring harness connector.
Below is a brief description of each:
NOTE: Checkout the 1992-1994 2.4L Nissan D21 ignition system wiring diagram here: 1992-1994 2.4L Nissan D21 Pickup Ignition System Wiring Diagram.
Here's a brief description of each terminal:
|1992-1994 D21 Ignition Coil Connector|
|1||Blue||IGC -Ignition coil control signal|
|2||Black with white stripe||Power -Battery power|
Making Sure Spark Is Missing At All Spark Plug Wires
Before you start with the tests in this tutorial, you need to see if there's a lack of spark at all 4 spark plug wires. This step is super important!
If even one spark plug wire is sparking, then you can conclude that the ignition coil is functioning and by extension, that the power transistor (ignition control module) is working too.
So, if you have tested for spark and none of the spark plug wires are sparking, then proceed. If not, check for spark first.
One more thing: I recommend using a dedicated spark tester for all of your tests. This will ensure an accurate test result. I recommend using an HEI spark tester. This bad boy is not expensive and very, very accurate! You can find out where to buy it here: The HEI Spark Tester.
TEST 1: Testing For Spark Directly On The Ignition Coil Tower
Now that you have checked and confirmed that there's no spark coming out of all 4 spark plug wires, the next step is to check for spark directly on the ignition coil tower.
If the ignition coil sparks (at this point), then we can conclude that the high tension wire (that connects the coil to the distributor) and/or the distributor cap/rotor are defective.
Yes, the ignition coil's high tension wire, the distributor cap, and distributor rotor can stop transmitting spark and make you believe the ignition coil is bad.
If the ignition coil does not spark, then the next step is to make sure that the ignition coil is getting power.
These are the test steps:
Disconnect the high tension wire that connects to the middle tower of the distributor cap.
NOTE: This is the high tension wire that connects the ignition coil to the distributor cap.
Place the HEI spark tester directly on the ignition coil tower. Ground the spark tester, using a battery jump start cable, to the battery negative (-) post.
Have your helper crank the engine as you secure the spark tester on top of the ignition coil tower
The spark tester should spark as the engine turns if the ignition coil is functioning.
Let's take a look at what your test results mean:
CASE 1: The ignition coil sparked away. This is the correct and expected test result and tells you that your Nissan D21's ignition coil is not defective.
You can correctly conclude that the ignition coil's high tension wire and/or the distributor cap/rotor are defective and behind your Nissan D21's 'no spark no start' problem and need to be replaced.
CASE 2: The ignition coil did not spark away. The next step is to make sure the ignition coil is getting power. For this test, go to: TEST 2: Making Sure The Ignition Coil Is Getting Power