Buy Ford Ranger Ignition Coils

The Ford Ranger's ignition coil-also called a coil pack, spark coil, or ignition transformer-boosts the truck's 12-volt battery power up to about 20,000-40,000 volts, giving the spark plugs enough energy to ignite fuel and keep the engine running smoothly. (carVertical, Delphiautoparts) Ford used two main styles: a waste-spark coil pack on 1990s-2011 models and coil-on-plug (COP) units on 2019-present EcoBoost Rangers. (Wikipedia, The Ranger Station) Common failure clues include misfires, rough idle, hard starts, poor mileage, and an illuminated check-engine light. (Ranger5G, carVertical) Routine checks-such as measuring primary resistance (0.3-1.0 Ω) (JustAnswer) and using dielectric grease on boots-help the coil last longer. Replacement is straightforward (two or four fasteners, 10 Nm torque on COP retainers) (The Ranger Station) and usually takes under 30 minutes with basic tools. A quick VIN search at the NHTSA recall portal confirms there are no outstanding safety campaigns for your truck.

An ignition coil is a tiny transformer made of two wire windings around an iron core. When battery current stops, the collapsing magnetic field sends a high-voltage pulse to the spark plug. (Wikipedia) Early Ranger engines used a single coil pack mounted near the passenger-side firewall; later engines give each plug its own COP unit to shorten the spark path and improve timing accuracy. (ranger-forums.com, The Ranger Station)

Primary side-a few hundred turns-charges on 12 V. When the engine computer breaks the circuit, energy transfers to the secondary side-thousands of turns-creating the big spark. (Delphiautoparts) The higher the turn ratio, the hotter the spark. Modern coils can deliver up to 40 kV under heavy load. (carVertical)

1990s-2011 (2.3 L, 3.0 L, 4.0 L) - Waste-spark coil pack fires two cylinders at once; spark-plug wires carry energy from the pack to each plug. (Wikipedia)
2019-present (2.3 L EcoBoost) - Four COP units sit directly on the plugs; each has its own small bolt (10 Nm) and electrical connector. (The Ranger Station)
The change cuts down on misfire codes and lets the PCM fine-tune timing for better power and emissions. (forum.autosportlabs.com)

Rough Idle & Shudder - weak spark lets fuel burn unevenly. (Ranger5G)
Random Misfire (P0300-P0306) - especially under load or rain. (YouTube)
Hard Starts - poor voltage means longer cranking. (carVertical)
Poor Mileage & Power Loss - incomplete burn wastes fuel.
Water Ingress on 2019-2023 - TSB 21-2147 adds a cover where moisture drips onto COP boots. (Ranger5G)

1. Visual check-look for cracks or carbon tracking lines. (Delphiautoparts)
2. Primary resistance-0.3-1.0 Ω between B+ and each coil pin (use a digital ohmmeter). (JustAnswer)
3. Secondary resistance-5 kΩ-20 kΩ between paired towers on coil-pack years.
4. Swap test-move the suspect COP to another cylinder; if the misfire follows, the coil is bad. (ranger-forums.com)
5. Scan-tool check-look for high cylinder misfire counts or coil primary circuit DTCs. (Ranger5G)

A step-by-step Ranger COP swap video shows the whole job in under eight minutes. (YouTube) Key points:

• Disconnect battery; pull the electrical plug.
• Remove the 8 mm retaining stud; twist and lift the coil.
• Lightly coat the new boot with dielectric grease.
• Install the coil and tighten to 10 Nm (89 lb-in). (The Ranger Station)
  On spark-plug torque, use 12 Nm (106 in-lb) on 2.3 L EcoBoost plugs. (Ranger5G)

Some owners try "high-energy" aftermarket COPs claiming 15 %-20 % more spark, but forums note little seat-of-the-pants gain unless the original part was failing. (F150 EcoBoost, Bob Is The Oil Guy) A hotter coil may let you widen the spark-plug gap slightly for modified engines, yet reliability can drop if the windings overheat. (Focus ST Forums)

• Keep spark-plug gaps in spec (0.70-0.80 mm on 2019-up). (Ranger5G)
• Replace plugs every 100 k mi and boots when they feel brittle.
• Use dielectric grease to seal out water-especially after TSB 21-2147 repairs. (Ranger5G)
• Check recalls twice a year on the NHTSA site.
• Recycle old coils at metal-scrap or e-waste centers; copper and steel are reusable and shouldn't hit landfills. (Delphiautoparts)

Ford coil-pack Rangers (2.3/3.0/4.0) share the same six-tower pack across 1995-2011 model years; wiring and firing order differ, so label your plug wires first. (Instructables) COP Rangers (2019-present) require four identical coils labeled "DG-578" or equivalent. (The Ranger Station)

Q: What is a waste-spark coil pack?
A: It fires two plugs at once-one on compression, one on exhaust-cutting parts count and cost. (Wikipedia)

Q: Can I drive with a weak coil?
A: Short trips are possible, but unburned fuel can overheat the catalytic converter, so fix it soon. (carVertical)

Q: How do I know which coil is bad on a 4-cyl Ranger?
A: Swap coils between cylinders; if the misfire code moves, you've found the culprit. (ranger-forums.com)

Q: What resistance should I read with a meter?
A: About 0.3-1.0 Ω on the primary pins and 5 kΩ-20 kΩ on the secondary side. (JustAnswer)

Q: Why did water ruin my 2019 coil?
A: Some Rangers collect rainwater in the plug wells; Ford released TSB 21-2147 adding a drip shield and updated boots. (Ranger5G)

Q: Do performance coils add horsepower?
A: Tests show smoother idle and quicker starts, but power gains are minimal on a healthy stock engine. (F150 EcoBoost, Bob Is The Oil Guy)

Q: What torque spec should I use on the retaining bolt?
A: Tighten COP retaining bolts to 10 Nm (89 lb-in) and spark plugs to 12 Nm (106 in-lb). (The Ranger Station, Ranger5G)

Q: Is there a recall on Ranger ignition coils?
A: No federal coil-specific recall exists today, but always confirm at the NHTSA portal with your VIN. (NHTSA)

Q: Where can I learn the repair steps visually?
A: A free video guide walks through coil-pack replacement on 1998-2011 trucks.

By understanding how your Ford Ranger's ignition coil works, spotting early trouble signs, and following the simple service steps above, you'll keep the engine firing strong and your pickup ready for the road.