How To Test The Ignition Coils (1994-1995 3.0L V6 Toyota Camry)

If your 1994-1995 3.0L V6 Toyota Camry's engine is misfiring, there's a good chance that it could be a bad Coil-On-Plug (COP) ignition coil (it comes equipped with six of them).

In this tutorial, I'll walk you through a step-by-step process to diagnose and test the COP ignition coils on your Camry. With your test results, you'll know if one or more of your coils are faulty.

APPLIES TO: This tutorial applies to the following vehicles:

• 3.0L V6 Toyota Camry: 1994, 1995.

Wiring Diagrams:

• Ignition System Wiring Diagram (1994 3.0L V6 Toyota Camry).
• Ignition System Wiring Diagram (1995 3.0L V6 Toyota Camry).

1996-2001 Ignition Coil Tests: The following tutorial will help you test the ignition coils on the 1996-2001 3.0L V6 Toyota Camry:

• How To Test The Ignition Coils (1996-2001 3.0L V6 Toyota Camry).

What Does A COP Ignition Coil Do?

The 1994-1995 3.0L V6 Camry ditched the mechanical distributor ignition system for a distributorless ignition system (DIS).

Why? Because ditching the distributor meant avoiding all the wear, tear, and maintenance headaches that come with it. OK, I'm not gonna bullshit you —it was done to save Toyota a ton of money. I'll be real: you and I saving time and money on maintenance wasn't exactly their top priority.

Before we start testing them, I'll quickly cover what these COP ignition coils do. In a nutshell, as you turn the key to crank and start the engine:

1. The ignition coil receives 10 to 12 Volts on the black with orange stripe (BLK/ORG) wire of its 2-wire connector.
2. It also receives an activation signal from the igniter (ignition control module) on the other wire of its connector.
   • The color of these wires is unique to each ignition coil.

When both signals are present, the COP coil generates and delivers a high-voltage spark to the spark plug it's connected to. This spark then ignites the fuel-air mixture in the cylinder where the spark plug is threaded.

If one or more COP coils fail, you're gonna have engine performance issues, misfires, or an engine no-start problem.

Common Symptoms Of A Bad Ignition Coil

As I mentioned above, when an ignition coil fails, it's definitely gonna cause engine performance issues. These are some of the common signs of a bad COP coil:

• Misfiring: This means that one or more cylinders are not firing properly, which can cause your engine to run rough, jerk, or even stall.
• Rough idling: A bad COP coil can cause your engine to idle poorly, which means it might be running rough or stumbling.
• Engine won't start: If two or more COP coils fail, you might find that your engine won't start at all.
• Engine takes multiple attempts to get it started: Another symptom of a bad COP coil is when your engine takes multiple tries to get started.
• Bad gas mileage: When a cylinder is misfiring due to a bad ignition coil, it's essentially "dead" and not contributing to the engine's power. This means the other cylinders have to compensate for the "dead" one(s), resulting in poor gas mileage.
• Smell of raw gasoline coming out of the tailpipe: If a bad ignition coil fails to ignite the fuel in one or more cylinders, that unburned fuel exits the exhaust system as raw gasoline vapor. This creates a strong, noticeable smell of fuel coming from the tailpipe.

Now that we know what to look out for, let's move on to the tests!

What Tools Do I Need To Test The Ignition Coil?

Here are the three tools you'll need to test the ignition coils on your 1994-1995 3.0L V6 Toyota:

• Spark tester: This tool is a must have tool to get an accurate spark test result. You can use any spark tester. The one I recommend and use is the OTC HEI spark tester. You can see an example of this tool (and also buy it) here: OTC 6589 Electronic Ignition Spark Tester (at: amazon.com).
• Multimeter: We'll use the multimeter to check that the ignition coil is getting power. If you don't have one, here's the one I recommend: Tekpower TP8268 AC/DC Auto/Manual Range Digital Multimeter with NCV Feature, Mastech MS8268 Upgraded, MS88 (at: amazon.com).
• 12 Volt automotive test light: This test light will help us make sure the ignition coil is getting its activation signal in TEST 3. If you don't have one, here's my recommendation: Lisle 28400 Heavy Duty 12 Volt Test Light (at: amazon.com).

Where To Buy The Ignition Coils And Save

I'm recommending the Standard Motor Products UF204 Ignition Coil as the one you should purchase, since it's a well-known after-market brand. Once you get to amazon. Com thru the links below, you can also choose other brands too!

NOTE: Not sure if the ignition coil fits your particular vehicle? Don't worry. Once you click on the link and get to the site, they'll make sure it fits by asking you the particulars of your vehicle. If it isn't the right one, they find it for you.

TEST 1: Testing The Ignition Coil For Spark

The first thing we need to do, is to see if the ignition coils are firing spark. The test steps assume that you're testing all six of them.

Do you need to test them all? No. If you already know which cylinder is misfiring, test just that one. If you don't know which cylinder is misfiring, then test them all.

For the most accurate test result, you'll need a dedicated spark tester to check the COP ignition coil for spark. If you don't have one, you can always grab one from an auto parts store or online.

Let's get started:

1. 1

   Disconnect the ignition coil from its connector.

2. 2

   Remove the number 1 ignition coil from the engine.

3. 3

   Reconnect the ignition coil to its electrical connector.

4. 4

   Attach the spark tester to the spark plug boot of the ignition coil.

5. 5

   Crank the engine.

6. 6

   You'll see one of two results: spark or no spark.

7. 7

   Install the COP coil back to its place on the engine.

8. 8

   Repeat steps 1 thru 7 on the other COP ignition coils.

Let's interpret your test result:

CASE 1: All six ignition coils sparked. This is the correct and expected test result and it lets you know that the ignition coils are OK.

CASE 2: One or more ignition coils DID NOT spark. This usually means that the ignition coil is bad.

To make sure the ignition coil is bad, let's make sure it's getting power. For this test, go to: TEST 2: Making Sure The Ignition Coil Is Getting Power.

TEST 2: Making Sure The Ignition Coil Is Getting Power

All of the ignition coils have two wires coming out of their connector. One wire, the black with orange stripe (BLK/ORG) which is shared by all six ignition coils, delivers 10 to 12 Volts

The other wire, which is an unique color for each ignition coil, delivers the ignition coil's activation signal.

In this test section, we're gonna check that the BLK/ORG wire is delivering power to the non-sparking ignition coil.

These are the test steps:

1. 1

   Disconnect the ignition coil from its 2-wire connector.

2. 2

   Set your multimeter to Volts DC mode.

3. 3

   Connect the black multimeter test lead to the battery negative post.

4. 4

   Probe the terminal that corresponds the white with red stripe wire.

5. 5

   Turn the ignition switch to the ON position but don't crank the engine.

6. 6

   Your multimeter should register 10-12 Volts.

Let's interpret your test result:

CASE 1: 10 to 12 Volts are present. This is the correct and expected test result.

Your next step is to make sure the non-sparking ignition coil is getting its activation signal. Go to: TEST 3: Making Sure The Ignition Coil Is Getting Its Activation Signal.

CASE 2: 10 to 12 Volts ARE NOT present. Without this voltage, the ignition coil is not gonna create and deliver spark to its spark plug.

The most likely cause of this missing voltage is:

• The ignition coil's connector is bad. The BLK/ORG wire has become disconnected from its female terminal.
• The BLK/ORG wire has an open-circuit problem.

Although its beyond the scope of this tutorial to troubleshoot this issue, your next step is to find out why this voltage is missing at this connector and restore it.