Honda GX390 No Spark? Here’s Everything You Need to Know

Has your truck been malfunctioning lately? Is it your Honda GX390 that has been acting weird lately? Could it be due to the no spark issue on your Honda GX390?

When there is no electrical spark to ignite the combustion of the engine, your Honda GX390 is struck with no spark issue. At this situation, the GX390 is not able to produce power and run the vehicle.

Throughout this whole article, we will thoroughly explore the problems regarding the no spark issue and delve into the fixation. Once you read this article, we assure you will be able to fix the problem in no time.

Honda GX390 No Spark Here's Everything You Need to Know

What is the no-spark issue on Honda GX390?

Honda GX390 is a spark-ignition engine, which means that there is an ignition switch that ignites the combustion.

The air-fuel mixture is located inside the combustion chamber of the internal combustion engine.

When the switch produces no spark, the initiation is stopped. The fuel mixture does not get the energy/ spark to initiate the combustion reaction.

Therefore, no further energy is transferred throughout the system, and the vehicle does not work.

What causes Honda GX390 no spark issues?

The cause of the no-spark problem eventually boils down to several problems. Generally, the spark-ignition system is made up of a handful of parts that all work in synchronization to carry out the initiation.

So, when one part fails to work/ is faulty, the other parts cannot work properly. This leads to the failure of the electrical spark. Here is the list of the causes for the Honda GX390 no spark problem.

  1. Defective Crankshaft Position Sensor
  2. Loose/ Torn WIres from the Crankshaft position sensor to the PCM
  3. Faulty Ignition Module
  4. Bad Ignition Coil
  5. Faulty Ignition Switch
  6. Faulty Engine Control Module (ECM)

What are the symptoms of the no spark issue on your Honda GX390?

Just like every problem, there are some indicators to signal/ detect the problem beforehand. Such is also the case for Honda GX390 with no spark issues. 

Whenever your heavy-duty vehicle has a no spark issue, these are likely to be the symptoms. They include:

  • Engine cranking up/ making the noise but not booting up the car
  • Stalling of the engine and does not restart when done.
  • Vigorous shaking of the engine while the car is in idle mode.
  • The car/ vehicle might stop in the middle of driving
  • Lack of power/ losing power while driving the car

How to fix the Honda GX390 no spark problem?

Now that you know the symptoms and causes, it is time we head for the main part. The section where we tell you how you can diagnose the problem and fix it. 

We have found out that there are four ways by which you eliminate the issue. We will proceed to show you them now.

Method 1: Replacing the ECM (Engine Control Module)

The Engine Control Module is the heart of the engine, as it controls everything. It monitors the GX390 and sends signals/ instructions to carry out tasks.

When they become faulty, it can stop the ignition process. Here is how you can replace it.

  1. Disconnect the negative terminal of the battery.
  2. Take off the hood and locate the ECM. It should be under the dashboard of either of the seats.
  3. Unlock the locks of the ECM. Generally, there are 3 of them, and you can easily unlock them. Once done, it should disconnect the electrical supply to the ECM.
  4. Unscrew the bolts holding the ECM.
  5. Replace the ECM and reinstall everything back into its place.

Method 2: Replacing the ignition switch

Ignition Switch
Ignition Switch

The ignition switch is a crucial part of the cart’s initiation process. The initiation process goes missing when it gets faulty, and hence the no spark issue appears. Here is how you can replace it.

  1. Disconnect the negative end of the battery.
  2. Unscrew the bolts from the bottom steering column cover of the dashboard.
  3. Once that is out of the way, do the same thing for the upper steering column cover. You can also take it out by pulling it gently.
  4. Pull out the clips holding the ignition switch and then put in the key. Turn it to accessory mode.
  5. Use a knife/screwdriver and pull out the ignition switch gently.
  6. Replace it with the one where the ignition switch matches the patterns on your key lock.

Method 3: Replacing the ignition coil

A small part that channels the voltage into the car to run is the ignition coil. Without it, the car will not be able to start. Here is how you can replace the ignition coil.

  1.  Disconnect the negative terminal of the battery.
  2. Locate the coil by looking up at your vehicle model manual.
  3. Once located, mark the plugs and cables using a marker and unplug them accordingly.
  4. Release the clip on the plug on the side.
  5. Unscrew the bolts holding the ignition coil framework. Once that is taken out, you can take out the ignition coil easily.
  6. Replace it with the new one and reinstall everything back into its place.

Method 4: Replacing the ignition module

Also known as the controller, the ignition module controls the rate of the ignition sparks. This is the process through which you can replace the ignition module easily.

  1. Disconnect the negative terminal of the battery first.
  2. Remove the air cleaner and the air filter by unplugging the wires and bolts.
  3. Once you are done with it, move on to the distributor cup. Remove the bolts and move them to the side. It would be best if you did not touch the spark wires as a change in orientation can change the rate of ignition sparks significantly.
  4. After that, remove the black plastic module. 
  5. When you reinstall the new one, remember to add some grease around it to allow it to be lubricated from the beginning.

Frequently Asked Questions (FAQs)

We believe that you have attained the knowledge you have come here for. However, there still might be some doubts lingering in your mind. Here are some FAQs we have arranged to clear your doubts further.

Can this no-spark issue come back again on my Honda GX390?

Yes, it can. It is not a one-time issue, so you need to be careful with your engine and take good care of it. However, we have told you all the ways you can fix the issue. So, we believe you will not face any problems when you tackle this issue again.

What are the prices of the replacement parts?

The prices vary with time and the methods. Replacing the ECM will cost you around $900, the ignition coil about $400, the ignition switch about $500, and the ignition module about $400.
If you are doing the replacements with the help of a professional, add an extra hundred dollars for labor costs.

What if I cannot do the replacements/ fixes to my Honda GX390 by myself?

You do not need to worry about this at all! Head over to the local automotive garage and consult with a professional. He/ She shall do all the replacements/ fixes for you. You will need to add a labor cost fee to your budget.

Can this no-spark issue on Honda GX390 harm my engine?

Yes, it can! If you continue to leave the issue on your car and continue to ignore it, then it can affect the other components. Therefore, we advise you to quickly fix the issue as soon as you notice/ diagnose it.


We believe that this article was quite informative and able to provide you with what you required. In this article, we showed you everything that is related to no spark issue in your Honda GX390.

Before we head out, we would love to share one crucial tip. That is to turn off the negative terminal of the battery every time you try to diagnose anything. The removal of the negative terminal is to prevent you from getting an electric shock.

You should be able to breeze through the process and get the job in no time. We wish you all the very best!

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