The Chrysler 318 engine, part of the LA-series small-block V8 family, has been a cornerstone of American automotive engineering for decades. Known for its reliability and versatility, this engine powered everything from Dodge trucks to Plymouth cars.
A critical aspect of its smooth operation is its firing order, which ensures that the engine runs efficiently, delivering power and longevity. This guide provides an in-depth look at the 318 firing order, its importance, common issues, and maintenance tips.
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What Is the Firing Order?
The firing order of an engine refers to the specific sequence in which the cylinders ignite their air-fuel mixture to produce power. For the Chrysler 318 engine, the firing order is:
- 1-8-4-3-6-5-7-2
This sequence is standard for small-block V8 engines in the Chrysler family. It’s designed to optimize balance, performance, and efficiency.
Why the Firing Order Matters
The firing order is essential to the proper functioning of the 318 engine. Here’s why it’s important:
- Smooth Engine Operation
The firing order ensures that power strokes are evenly distributed across the engine’s crankshaft, reducing vibrations and providing a smoother ride. - Efficient Power Delivery
Proper firing ensures consistent crankshaft rotation, maximizing the engine’s ability to produce power efficiently. - Fuel Economy
A correctly timed firing order optimizes combustion, reducing wasted fuel and improving overall efficiency. - Durability
Balanced firing reduces wear and tear on the engine’s internal components, including the crankshaft, pistons, and bearings.
Understanding the 318 Engine Layout
To grasp how the firing order works, it’s essential to understand the layout of the 318 engine:
V8 Configuration
The 318 is a V8 engine, meaning it has eight cylinders arranged in a “V” shape, with four cylinders on each bank.
Cylinder Numbering
The cylinders are numbered as follows:
- Driver’s Side (Bank 1): 1, 3, 5, 7
- Passenger’s Side (Bank 2): 2, 4, 6, 8
Cylinder 1 is located at the front of the engine on the driver’s side, closest to the timing chain.
Crankshaft Timing
The crankshaft design and camshaft timing ensure that each cylinder fires at the right moment, based on the firing order.
Symptoms of Firing Order Issues
When the firing order is disrupted, the 318 engine may exhibit noticeable symptoms. Here are the most common issues:
- Engine Misfires
A misfire occurs when a cylinder fails to ignite properly, resulting in a rough-running engine and loss of power. - Rough Idling
Incorrect firing order can cause the engine to vibrate excessively or idle unevenly, especially at low RPMs. - Power Loss
A disrupted firing order prevents the engine from delivering smooth and consistent power. - Poor Fuel Efficiency
Misfires and incomplete combustion waste fuel, reducing the engine’s miles per gallon (MPG). - Check Engine Light
Modern vehicles equipped with the 318 engine may illuminate the check engine light when firing order problems are detected. - Excessive Exhaust Smoke
A disrupted firing order may cause unburned fuel to exit through the exhaust system, producing excessive smoke.
Diagnosing Firing Order Problems
If you suspect firing order issues in your 318 engine, follow these diagnostic steps:
Inspect the Ignition System
- Check the spark plugs for fouling, wear, or damage. Replace any that are worn out.
- Inspect the spark plug wires for cracks or loose connections, ensuring they follow the 1-8-4-3-6-5-7-2 sequence.
- Examine the distributor cap and rotor for corrosion or misalignment.
Use a Timing Light
- Attach a timing light to verify that each cylinder is firing at the correct time.
Perform a Compression Test
- Use a compression gauge to test each cylinder. Low compression in one or more cylinders can indicate valve or piston issues affecting firing.
Scan for Diagnostic Trouble Codes (DTCs)
- Connect an OBD-II scanner to identify error codes related to misfires or ignition timing.
Check the Timing Chain or Belt
- Inspect the timing chain or belt for wear or misalignment, which can disrupt the firing sequence.
Fixing Firing Order Problems
Once you’ve identified the cause, follow these steps to fix firing order problems:
Replace Faulty Spark Plugs
- Install new spark plugs that meet Chrysler’s specifications for the 318 engine. Ensure the plugs are properly gapped.
Replace Spark Plug Wires
- Replace any damaged or worn spark plug wires. Ensure they are connected in the correct firing order.
Repair or Replace the Distributor
- Replace a damaged distributor cap or rotor. Align the rotor correctly to match the firing sequence.
Adjust the Timing
- Use a timing light to set the ignition timing according to the factory specifications.
Replace the Timing Chain or Belt
- If the timing chain or belt is worn, replace it and realign the camshaft and crankshaft to ensure proper timing.
Address Sensor Issues
- Replace faulty sensors, such as the crankshaft position sensor, if they are causing incorrect timing signals.
Preventing Firing Order Problems
Preventive maintenance is the key to avoiding firing order issues and ensuring the longevity of your 318 engine. Follow these tips:
- Regular Tune-Ups
Schedule periodic inspections of the ignition system, including spark plugs, wires, and the distributor. - Use Quality Components
Invest in high-quality spark plugs, ignition wires, and distributor parts to ensure reliable performance. - Monitor Engine Performance
Pay attention to changes in fuel efficiency, acceleration, or engine noise, as these may indicate firing order problems. - Replace Timing Components as Needed
Replace the timing chain, belt, or tensioners according to the manufacturer’s recommendations. - Follow Maintenance Schedules
Adhere to Chrysler’s recommended service intervals for the 318 engine.
FAQs About the 318 Firing Order
Why is the firing order important?
The firing order ensures balanced power delivery, efficient combustion, and reduced engine stress.
Can I adjust the firing order myself?
Yes, if you’re comfortable with engine mechanics. Ensure the spark plug wires are connected correctly, and use a timing light to verify ignition timing.
What happens if the firing order is incorrect?
An incorrect firing order causes misfires, vibrations, power loss, and potential engine damage.
Is the 1-8-4-3-6-5-7-2 firing order unique to the 318?
No, this firing order is common among Chrysler small-block V8 engines.
Engines with Similar Firing Orders
- 2003 Dodge Durango Firing Order
- 2014 Dodge Durango Firing Order
- 2006 Dodge Durango Firing Order
- 2004 Dodge Durango Firing Order
- 2005 Dodge Durango Firing Order
Conclusion
The 318 firing order, 1-8-4-3-6-5-7-2, is fundamental to the engine’s performance and reliability. By ensuring smooth power delivery, efficient combustion, and minimal vibrations, the firing order supports the engine’s longevity and performance. Understanding the firing order, recognizing symptoms of issues, and maintaining the ignition system are essential for keeping your 318 engine running at its best. With proper care, this iconic engine will continue to deliver reliable performance for years to come.
