09 Nissan Murano Firing Order

Okay, let's talk about the firing order for a 2009 Nissan Murano. Getting this right is absolutely crucial for proper engine operation, timing, and overall performance. Messing it up can lead to misfires, poor fuel economy, and even engine damage. This guide assumes you have a good understanding of basic engine mechanics, including how spark plugs, ignition coils, and the crankshaft work. If you’re unsure about any of these, it's best to consult a more fundamental tutorial first.

Understanding Firing Order

First, let's define what firing order actually is. It’s the sequence in which the cylinders in your engine fire. Each cylinder contains a piston that moves up and down, compressing the air-fuel mixture. At the top of its compression stroke, the spark plug ignites the mixture, forcing the piston down and generating power. The firing order dictates which cylinder gets ignited next.

The 2009 Nissan Murano uses the VQ35DE engine, a 3.5-liter V6. This configuration means you have two cylinder banks, each containing three cylinders. The standard firing order for the VQ35DE engine, and therefore the 2009 Murano, is:

1-2-3-4-5-6

This simple sequence is essential, but we need to know *where* these cylinder numbers are located on the engine.

Cylinder Numbering and Bank Identification

Here’s where things get a bit more specific. Understanding the cylinder numbering convention is paramount. Imagine you're standing in front of the Murano, looking under the hood. The engine is mounted transversely (sideways), but for numbering purposes, we imagine it oriented as if in a rear-wheel-drive car.

The right bank (the bank closer to you) is generally referred to as Bank 1. The left bank (the bank further away) is Bank 2.

• Bank 1 Cylinders: 1, 3, 5 (from front to back)
• Bank 2 Cylinders: 2, 4, 6 (from front to back)

So, to reiterate:

• Cylinder 1: Front cylinder on the right bank (Bank 1)
• Cylinder 2: Front cylinder on the left bank (Bank 2)
• Cylinder 3: Middle cylinder on the right bank (Bank 1)
• Cylinder 4: Middle cylinder on the left bank (Bank 2)
• Cylinder 5: Rear cylinder on the right bank (Bank 1)
• Cylinder 6: Rear cylinder on the left bank (Bank 2)

Make sure you understand this numbering before proceeding! Visual aids (diagrams) are immensely helpful here. Search online for "VQ35DE cylinder numbering" for clear pictures.

Ignition Coil Pack Configuration

The VQ35DE engine uses a coil-on-plug (COP) ignition system. This means each spark plug has its own dedicated ignition coil directly attached to it. This eliminates the need for a distributor and spark plug wires, providing a more reliable and efficient spark. So, knowing the firing order also tells us the order in which the ignition coils need to fire.

The ignition coils are usually numbered or can be identified by their position relative to the cylinders. The firing order (1-2-3-4-5-6) directly corresponds to the order in which these ignition coils need to be triggered by the engine control unit (ECU).

Troubleshooting Misfires Related to Firing Order

If your Murano is experiencing misfires, rough idling, or a loss of power, a firing order issue could be the culprit. Here's how to troubleshoot:

1. Check for Diagnostic Trouble Codes (DTCs): Use an OBD-II scanner to read any stored codes in the ECU. Codes like P0300 (Random Misfire Detected), P0301 (Cylinder 1 Misfire), P0302 (Cylinder 2 Misfire), etc., can give you valuable clues.
2. Inspect Ignition Coils: Visually inspect each ignition coil for cracks, damage, or signs of arcing. You can also use a multimeter to test the primary and secondary resistance of the coils. Compare the readings to the specifications in the repair manual. A significantly different reading suggests a faulty coil. Swap coils between cylinders and see if the misfire code follows the coil. If it does, you've confirmed the coil is the problem.
3. Check Spark Plugs: Remove and inspect each spark plug. Look for signs of fouling (carbon buildup), oil contamination, or wear. The condition of the spark plug can tell you a lot about the health of the cylinder. Replace spark plugs at the manufacturer's recommended intervals.
4. Verify Injector Function: Fuel injectors deliver fuel into the cylinders. A faulty injector can cause a misfire. You can use a multimeter to check the injector's resistance or listen for a "clicking" sound when the engine is running (indicating it's opening and closing). Professional fuel injector cleaning services can help restore proper function.
5. Compression Test: A cylinder with low compression won't fire correctly, regardless of the firing order or ignition system. Perform a compression test on each cylinder and compare the readings. Significant variation between cylinders indicates a potential issue with valves, piston rings, or head gasket. This is a more involved test, and requires specific tools and knowledge.
6. Check Wiring Harness and Connectors: Inspect the wiring harness and connectors leading to the ignition coils and fuel injectors. Look for damaged wires, loose connections, or corrosion. Use a multimeter to check for continuity and voltage at the connectors.
7. ECU Issues (Rare): In rare cases, a faulty ECU can cause misfires. If you've ruled out all other possibilities, consider having the ECU tested by a qualified technician.

Common Mistakes to Avoid

• Incorrect Cylinder Identification: This is the most common mistake. Double-check your cylinder numbering before making any changes. Refer to diagrams and service manuals.
• Assuming a Single Cause: Misfires can have multiple causes. Don't assume that the firing order is the only problem. Thoroughly investigate all potential issues.
• Using Generic Information: VQ engines have been around for a while, but subtle differences exist between years and models. Always refer to information specific to your 2009 Nissan Murano.
• Ignoring Maintenance: Regular maintenance, including spark plug replacement and fuel injector cleaning, can help prevent misfires and other engine problems.

Tools Required

Here's a list of tools you'll likely need:

• Socket set
• Wrench set
• Spark plug socket
• Torque wrench
• Multimeter
• OBD-II scanner
• Compression tester (if performing a compression test)
• Service manual (for torque specifications and other information)
• Safety glasses and gloves

Final Thoughts

Understanding the firing order of your 2009 Nissan Murano is crucial for diagnosing and resolving engine performance issues. By carefully following the steps outlined in this guide and using the appropriate tools, you can effectively troubleshoot misfires and ensure your engine runs smoothly. Always prioritize safety and consult a qualified mechanic if you're unsure about any procedure.

Disclaimer: This information is for educational purposes only and should not be considered a substitute for professional advice. Working on your car can be dangerous, so always take appropriate safety precautions. If you are not comfortable performing these procedures, consult a qualified mechanic.