If you own a Chevy or GMC truck, van, or SUV with a 350 TBI engine, you may have experienced problems with the ignition system. The ignition module is a vital component of the engine’s ignition system, and when it malfunctions, it can cause a range of symptoms that can be frustrating and potentially dangerous.
In this article, we will take a deep dive into 350 TBI bad ignition module symptoms and provide you with valuable insights into how to diagnose and fix the issue.
Contents
What is a 350 TBI Ignition Module, and How Does it Work?
The 350 TBI (Throttle Body Injection) ignition module is an electronic component that controls the engine’s ignition timing and firing sequence. It receives signals from the distributor and the engine control module (ECM) to determine when to fire each spark plug.
The ignition module works by using electronic components to switch the primary voltage to the ignition coil on and off rapidly. This action causes a magnetic field to build up and collapse, inducing a high voltage in the secondary coil that fires the spark plugs.
350 TBI Bad Ignition Module Symptoms
Here are some symptoms of a bad ignition module –
Engine Misfires: One of the most common symptoms of a bad ignition module is engine misfires. You may notice a hesitation or stumbling feeling when accelerating, or the engine may start to run rough at idle.
Starting Problems: If your engine cranks but doesn’t start or starts and stalls shortly after, it could be due to a faulty ignition module.
Stalling: A bad ignition module can cause the engine to stall while driving, which can be dangerous, especially on highways or busy roads.
Poor Fuel Economy: A faulty ignition module can cause the engine to burn more fuel than usual, resulting in poor fuel economy.
Loss of Power: A bad ignition module can cause a loss of power, which can be felt during acceleration or when climbing hills.
No Spark: If you are not getting any spark from the ignition coil, it could be due to a bad ignition module.
Check Engine Light: A bad ignition module can trigger the check engine light, indicating a problem with the engine’s ignition system.
Rough Idle: If your engine is idling roughly, it could be due to a faulty ignition module.
Backfiring: A bad ignition module can cause the engine to backfire, which can be heard as a popping or banging noise from the exhaust.
Overheating: A faulty ignition module can cause the engine to overheat, which can result in engine damage or failure.
Diagnosing a Bad Ignition Module
If you are experiencing any of the symptoms mentioned above, you should consider diagnosing your ignition module. Here are some steps you can take to diagnose a bad ignition module:
Check the Spark Plugs: Check the spark plugs to ensure they are not fouled or worn. If they are, replace them and see if the symptoms improve.
Check the Ignition Coil: Use a multimeter to test the ignition coil’s primary and secondary resistance. If the resistance is out of range, replace the ignition coil.
Check the Ignition Control Module: Use a test light or voltmeter to check the ignition control module’s power and ground connections. If there is no power or ground, check the wiring and connections. If everything is okay, replace the ignition control module.
Check the Distributor Cap and Rotor: Inspect the distributor cap and rotor for signs of wear or damage. If you notice any damage, replace the distributor cap and rotor.
Check the Wiring: Inspect the wiring from the ignition module to the distributor for any damage, corrosion, or loose connections. If any issues are found, repair or replace the wiring as necessary.
Test the Ignition Module: Use an ignition module tester or a scope to test the module’s output. If the module is not producing a signal or is producing an erratic signal, it may be faulty and should be replaced.
How to Replace a Bad Ignition Module
If you have diagnosed a bad ignition module, it is time to replace it. Here are some steps to follow:
Disconnect the battery: Before starting any work, disconnect the negative battery cable to avoid any electrical hazards.
Locate the ignition module: The ignition module is usually located on the distributor or mounted on the firewall.
Remove the old module: Disconnect the wiring harness and remove the old module from its mounting location.
Install the new module: Install the new module in its mounting location and reconnect the wiring harness.
Reconnect the battery: Reconnect the negative battery cable.
Test the ignition system: Start the engine and test the ignition system to ensure that it is functioning correctly.
Frequently Asked Questions
Here are some FAQs about 350 TBI bad ignition module symptoms –
Q: Can a bad ignition module cause a no-start condition?
A: Yes, a bad ignition module can cause a no-start condition. If the ignition module fails to send a signal to the ignition coil, the engine will not start.
Q: How often should I replace my ignition module?
A: There is no set interval for replacing the ignition module. However, it is recommended to replace it every 50,000 to 100,000 miles or when symptoms of failure arise.
Q: What is the cost to replace an ignition module?
A: The cost of replacing an ignition module can vary depending on the make and model of the vehicle and the labor cost. Generally, the cost can range from $100 to $300.
Q: How can I prevent ignition module failure?
A: Regular maintenance of the ignition system, such as changing spark plugs and wires, can help prevent ignition module failure.
Q: How do I know if my ignition module is failing?
A: Common symptoms of a failing ignition module include engine misfires, starting problems, stalling, poor fuel economy, and loss of power.
Conclusion
A bad ignition module can cause a range of symptoms that can affect your vehicle’s performance and safety. If you experience any of the symptoms mentioned above, it is essential to diagnose and replace a faulty ignition module promptly. Regular maintenance of the ignition system can help prevent ignition module failure and prolong the life of your engine.
Understanding the 350 TBI bad ignition module symptoms and how to diagnose and replace it can save you time and money in the long run. By following the steps and tips provided in this article, you can keep your 350 TBI engine running smoothly and prevent any unexpected breakdowns.
So, if you suspect your ignition module is failing, don’t wait until it’s too late. Take action today and keep your engine running strong.