Ignition and Tune-Up Guide
Introduction to Ignition and Tune-Up for W-Body Vehicles
Your vehicle’s ignition system plays a crucial role in ensuring optimal engine performance and longevity. Whether you’re driving a classic W-body model like the Pontiac Grand Prix, Chevrolet Lumina, Oldsmobile Cutlass Supreme, or Buick Regal, maintaining the ignition system and performing regular tune-ups is essential for keeping your car running smoothly. At WBodyTech.com, we understand the importance of these systems and how they impact everything from engine power to fuel efficiency.
This guide covers everything you need to know about the ignition system and tune-up procedures for W-body cars.
We’ll dive into the core components, such as spark plugs, and ignition coils, and explain how regular maintenance can prevent common issues like misfires, poor acceleration, and starting difficulties. Proper tune-ups will not only help restore lost performance but also improve reliability and fuel economy.
Whether you’re a seasoned DIY mechanic or just starting to get hands-on with your W-body car, this guide will provide step-by-step instructions, tips, and recommendations on how to keep your vehicle’s ignition system in top shape. Explore the sections below for specific maintenance, troubleshooting tips, and upgrade suggestions to enhance performance and ensure your W-body car stays road-ready.
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Tools needed for this job:
- Spark plug socket
- Ratchet and extension
- Torque wrench
- Spark plug gap tool
- 5.5mm Socket
- 7mm Socket
- CRC QD Electronic Cleaner
- CRC Di-Electric Grease
- Soft copper wire brush
- Replacement spark plugs and ignition coils (if necessary)
- A new plug wire set is recommended for the best results
Step-by-Step Guide
1. Preparation
- Ensure the engine is cool before starting.
- Disconnect the negative battery terminal to prevent any electrical shorts
2. Removing Old Wires & Spark Plugs
- Locate the spark plugs. They are usually found on the top or side of the engine depending on OHV or DOHC Engine.
- Label and Remove all plug wires from the coils (firing order can be found below for the 3800 and the 60° V6)
3. Inspecting and Gapping New Spark Plugs
- Check the gap on the new spark plugs using a spark plug gap tool. Adjust the gap according to your vehicle’s specifications.
- Apply a small amount of dielectric grease to the threads of the new spark plugs.
4. Installing New Spark Plugs
- Carefully thread the new spark plugs into the engine by hand to avoid cross-threading.
- Use the torque wrench to tighten the spark plugs to the manufacturer’s recommended torque specification.
5. Replacing Ignition Coils
- Using the 5.5mm Socket, remove both screws from each coil pack
- Using the 7mm socket, unscrew the connector from the bottom of the module (60° V6 just have 3 plugs)
6. Prepping, and cleaning the coils and module.
- Using the Electronic Cleaner, spray the top and bottom of the coils where they connect to the wire and tabs, clean using the copper brush.
- Using the Electronic Cleaner again, clean the connections on the module at the point where the coils connect and the connector(s) itself.
- Using the Electronic Cleaner one last time, clean the connector(s) from the engine harness.
- Let dry.
- Once everything is dry, apply the Di-Electric Grease to all connections, coil top and bottom, module connector(s), and plug boots.
- Install the new coils in the reverse order, ensuring all connections are secure.
7. Reconnecting the Battery
- Reconnect the negative battery terminal.
- Start the engine to ensure everything is functioning correctly.
Tips for Optimal Performance
- Regularly check and replace spark plugs and ignition coils as part of your vehicle’s maintenance schedule.
- Use high-quality replacement parts to ensure longevity and performance.
- Keep the ignition system clean and free of debris to prevent misfires and other issues.
By following this guide, you can maintain your GM W-Body car’s ignition system, ensuring reliable performance and longevity.
Firing Order
2.8, 3.1 & 3.4 Firing Order

3100 & 3400 Firing Order

3800 Firing Order

Spark Plugs
2.8 V6 & 3.1 V6
- ACDelco Copper Part # R44LTSM
- Autolite Copper Part # 5245
- Plug Gap 0.45
3.1 Turbo Vin V
- ACDelco Copper Part # R42LTS
- Autolite Copper Part # 103
- Plug Gap 0.45
3.4 DOHC V6
- ACDelco Iridium Part # 41-993
- Autolite XP Iridium Part # XP5243
- Autolite Copper Part # 5243
- Plug Gap 0.45
3100 & 3400 V6
- ACDelco Double Plat Part # 41-940
- Autolite Copper Part # 606
- Plug Gap 0.60
3.6 DOHC V6
- ACDelco Iridium Part # 41-109
- Autolite XP Iridium Part # XP5263
- Autolite Platinum Part # AP5263
- Plug Gap 0.45
3800 N/A
- ACDelco Double Plat Part # 41-902
- Autolite Platinum Part # AP606
- Autolite Copper Part # 606
- Plug Gap 0.60
3800 SC
- ACDelco Double Plat Part # 41-902
- Autolite Platinum Part # AP606
- Autolite Copper Part # 606
- COLDER Autolite Copper Part # 104 & 103 (Requires Tune)
- Plug Gap 0.60
Wire Sets
2.8 & 3.1 V6
- Delphi / Wireset Part # XS10206
- ACDelco / Wireset Part # 9706R
- Duralast Gold / Wireset Part # D801163
3.4 DOHC V6
- Duralast Gold / Wireset Part # 4877
3100 & 3400 V6
- Delphi / Wireset Part # XS10226
- NGK / Wireset Part # 51107
- Duralast Gold / Wireset Part # D801096
3.6 DOHC V6
- NGK / Boots Part # 58984
- Duralast Gold / Boots Part # 90098
3800 V6
- AcDelco / Wireset Part # 9746BB
- NGK / Wireset Part # 51031
- Duralast Gold / Wireset Part # D801110
Coil Packs
Std Emotec Coil Packs:
Gray Bottom
Low voltage side (Bottom)
- 0.9
- 0.9
- 0.9
- 0.9
- 0.9
- 0.8
- 0.9
- 0.9
- 0.9
High voltage side (Top)
- 5800
- 5680
- 5750
- 5800
- 5800
- 5700
- 5810
- 5800
- 5700
L67 Coil Packs:
Blue Bottom
Low voltage side (Bottom)
- 0.8
- 0.9
- 0.9
- 0.9
- 0.9
- 0.9
- 0.8
- 0.9
- 0.9
High voltage side (Top)
- 5640
- 5730
- 5750
- 5800
- 5800
- 5750
- 5800
- 5800
- 5750
MSD Coil Packs:
Gray Bottom
Low voltage side (Bottom)
- 0.8
- 0.8
- 0.8
High voltage side (Top)
- 5660
- 5640
- 5790