Engine No-Start Ignition System Tests (1991-1994 1.5L Toyota Tercel)

If your 1991-1994 Toyota Tercel's engine won't start, it could be due to a lack of spark from one of the components that make up the ignition system going bad.

The cool thing is that we can easily troubleshoot this issue with a very systemic diagnostic approach and in this tutorial, I'll show you how.

By following this step-by-step tutorial, you'll learn how to accurately determine whether a faulty ignition system is preventing your Tercel from starting.

APPLIES TO: This tutorial applies to the following vehicles:

• 1.5L Toyota Tercel: 1991, 1992, 1993, 1994.

Ignition System Wiring Diagram:

• Ignition System Wiring Diagram (1991-1994 1.5L Toyota Tercel).

Igniter (Ignition Control Module) And Pickup Coil Tests:

• How To Test The Igniter (1991-1994 1.5L Toyota Tercel).
• How To Test The Distributor Pickup Coil (1991-1994 1.5L Toyota Tercel).

Ignition System Basics

The ignition system on your 1991-1994 Toyota Tercel's engine is responsible for generating the high-voltage spark needed to ignite the fuel-air mixture to start and keep it running.

However, when one or more ignition system components malfunction, you'll end up with an engine cylinder misfire problem or issues with engine starting.

To better wrap our heads around your Tercel's ignition system, let's explore its key components:

• Mechanical distributor: Responsible for distributing the high-voltage spark to the correct spark plug wire.
• Pick-up coil: Located inside the distributor. It generates low-voltage signals that trigger the fuel injection computer when the camshaft and crankshaft rotate.
• Distributor cap: This bad boy receives the high-voltage spark from the ignition coil and directs it to the correct spark plug wire via the distributor rotor.
• Distributor rotor: Located inside the mechanical distributor, it rotates as the engine turns over, aligning with the terminals in the distributor cap to ensure proper spark timing.
• Spark plug wires: These carry the high-voltage spark from the ignition coil through the distributor cap and out to the spark plugs.
• Igniter (ignition control module): Acts as a switch that triggers the ignition coil to produce a high-voltage spark.
• Ignition coil: Converts low-voltage signals into high-voltage pulses that are sent through the spark plug wires.

In this tutorial, we'll cover testing and diagnosing common issues with each component, helping you identify potential problems that might be preventing your Tercel's engine from starting or running correctly.

Engine No-Start Diagnostic Basics

When faced with an engine no-start issue in your Toyota Tercel, there's quite a few potential components, that if they've failed, will cause the engine to either misfire or not start.

Here are some common culprits to consider:

• Spark Plug Wires: Over time, the high tension wires will deteriorate and lose their ability to transmit spark from the distributor cap to the spark plugs. Having them all fail at the same time doesn't happen, but if a sufficient number of them are bad, your Tercel's engine isn't gonna start, especially in cold weather.
• Distributor Cap: The cap's metal terminals can become pitted and coated with carbon buildup due to electrical arcing and oxidation. If enough terminals are affected, spark is not reach those spark plugs those terminals are responsible for supplying spark to, resulting in an engine no-start problem.
• Distributor Rotor: The rotor's metal strip can also suffer from pitting and carbon buildup at the center contact point and terminal end, due to constant arcing and oxidation. Excessive buildup can prevent the spark from transferring to the cap terminals, leading to an engine no-start issue.
• Pickup Coil: Without the proper signals from the CKP (Camshaft Position) and CMP (Camshaft Position) the pickup coil generates, the computer cannot activate the igniter, which in turn will not activate the ignition coil. As a result, no spark is generated, and your Tercel's engine won't start.
• Faulty Igniter or Ignition Coil: If either component fails, the ignition system will not function properly, preventing the engine from starting due to a lack of spark.

What Tools Do I Need To Test The Ignition System?

Here are the three tools you'll need to test the ignition system on your 1991-1994 1.5L Toyota Tercel:

• Spark tester: A spark tester is important for an accurate spark test result. There are many you can choose from, the one I recommend using is the OTC HEI spark tester. You can view an example of this tool and purchase it here: OTC 6589 Electronic Ignition Spark Tester (at: amazon.com).
• Multimeter: A multimeter will help verify that the ignition coil is receiving power (TEST 4). If you don't have one, I recommend this one: 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 5. If you don't have one, this is the one I use and recommend: Lisle 28400 Heavy Duty 12 Volt Test Light (at: amazon.com).

Where To Buy The Ignition Coil 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 Tercel? 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: Checking The Spark Plug Wires For Spark

To diagnose your Tercel's no-start issue, we'll start by checking for spark at each spark plug wire. This is an important diagnostic step that will help us determine if a lack of spark is causing the problem.

To get an accurate test result, it's important that you use a dedicated spark tester. The spark tester I recommend (I use it and this bad boy works right out of the box) is the OTC 6589 Electronic Ignition Spark Tester. You can find more information and purchase this tool here: OTC 6589 Electronic Ignition Spark Tester (at: amazon.com).

Let's get started:

1. 1

   Disconnect the spark plug wire from its spark plug.

2. 2

   Connect the spark plug wire to the spark tester.

3. 3

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

4. 4

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

5. 5

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

6. 6

   Remove the spark tester and reconnect the spark plug wire to its spark plug.

7. 7

   Repeat steps 1 thru 6 on the remaining spark plug wires.

Let's interpret your test result:

CASE 1: All four spark plug wires sparked. This is the correct and expected test result and it tells you that the ignition system is NOT behind the engine's no-start problem.

You can also conclude that the following components are OK:

• The igniter (ignition control module).
• The ignition coil.
• The CMP and CKP sensors (located in the distributor).
• The distributor can and rotor.

If the engine isn't starting, it's not due to a fault in the ignition system.

CASE 2: Some, but not all, spark plug wires sparked. This usually means that the spark plug wires that did not spark are bad or that the distributor cap is bad.

To further diagnose this, go to TEST 3: Checking The Distributor Cap For Spark.

CASE 3: None of the spark plug wires sparked. This test result confirms that the engine isn't starting due to a lack of spark.

Your next step is to check that the ignition coil is sparking. Go to: TEST 2: Checking The Ignition Coil For Spark.

TEST 2: Checking The Ignition Coil For Spark

In most vehicles, the ignition coil is located outside the distributor. A high-tension wire connects the ignition coil to the distributor, delivering the spark generated by the coil.

However, in the 1991–1994 1.5L Toyota Tercel, the ignition coil is located inside the distributor. Instead of relying on a high-tension wire, the spark travels directly from the ignition coil to the distributor cap.

The distributor cap then channels the spark to the rotor, which distributes it to the metal terminals on the cap. From there, the spark travels through the spark plug wires to each of the four spark plugs.

In this test section, we'll remove the distributor cap and use a spark tester to check for spark directly at the ignition coil.

• If the ignition coil sparks, the issue likely lies with a faulty distributor cap or rotor, causing the engine's no-start condition.
• If there's no spark, we'll proceed to TEST 2 for further diagnosis.

OK, let's get going:

1. 1

   Remove the distributor cap from the distributor.

2. 2

   Connect the spark tester to the metal terminal on the ignition coil using black electrical tape (to allow the components to touch and remain in contact as the engine cranks).
   
   NOTE: Since the spark tester can't physically insert into the terminal, we'll use black electrical tape to wrap them together and create a metal-to-metal contact between the two. This ensures that the spark tester makes proper connection with the terminal.

3. 3

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

4. 4

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

5. 5

   You'll get 1 of 2 results: Spark or no spark.

Let's interpret your test result:

CASE 1: The spark tester sparked. This is the correct and expected test result.

You can conclude that the distributor rotor and cap are bad (and need to be replaced) if you have:

• Confirmed that all four spark plugs are not sparking (TEST 1).
• Confirmed in this test section that the ignition coil's high tension is sparking.

CASE 2: The spark tester DID NOT spark. This no-spark test result is usually caused by one of the following:

1. The ignition coil is bad.
2. The ignition coil isn't getting power.
3. The ignition coil isn't getting its activation signal (from the igniter).

Your next step is to check the ignition coil's voltage supply. Go to: TEST 4: Making Sure The Ignition Coil Is Getting Power.