How to Test the 2 Coil Packs
(Ford 4.6L, 5.4L)

Coil Pack Test: Troubleshooting Multiple Misfires (Ford 4.6L, 5.4L)

If your 4.6L Ford car (or pick up or SUV) equipped with the 2 coil pack Ignition System is misfiring (P0301, P0302, P0303, P0304, P0305, P0306, P0307, P0308), this is the article that will help you to troubleshoot those misfire codes.

The two most common problems, with this type of ignition system is either a BAD ignition coil or BAD spark plug wires, and this article will help you to troubleshoot both.

Important Tips and Suggestions

IMPORTANT: Before you jump into the tests, please read the following tips and suggestions:

TIP 1: This article will help you to diagnose the spark plug wires and the ignition coil packs.

TIP 2: I'll use the phrase ‘Paired Cylinders’ quite a bit. To successfully diagnose the misfire or ignition system on your 4.6L Ford vehicle, it's important that you understand what this means, so be sure and read the section ‘Coil Pack Basics’ before you start testing.

TIP 3: Think and breathe SAFETY the whole time you're physically doing these tests, since some of these tests require that you crank the engine.

If a helper is gonna' help you, have him or her wait outside the vehicle till you're ready to have him or her crank the engine (as you're setting up the test).

TIP 4: You'll notice that the photos and the testing instructions call for an HEI spark tester. If you don't have one, don't panic... you can use any other type of spark tester (although the results may not be as accurate). If you want to know the reason for the fixation on the HEI spark tester, go to section: Why the HEI Spark Tester..

Coil Pack Basics

What's gonna help you to easily find the BAD coil pack or the root cause of the misfire on your 4.6L Ford car or pick up (or SUV), is to know that each coil pack is made up of 2 individual ignition coils.

Here are some more specific details:

  1. Each individual ignition coil (within the pack) has two towers.
    1. This is the reason why each coil pack has 4 towers.
  2. These two towers fire spark to 2 different cylinders at the exact same time.
    1. cylinders that get spark at the exact same time are known as ‘Paired Cylinders’.
  3. Each coil pack has three wires
    1. One wire is the power source (12 volts).
    2. The other 2 wires provide the switching signal for each ignition coil.
    3. The switching signal is what activates the ignition coil (within the pack) to fire off spark.
  4. The coil pack on the passenger side of the engine feeds spark to:
    1. Cylinders 1 and 6.
    2. Cylinders 3 and 5.
  5. The coil pack on the driver side of the engine feeds spark to:
    1. Cylinders 4 and 7.
    2. Cylinders 2 and 8.
  6. The most important thing to remember is that the two cylinders that get spark at the exact same time are referred to as ‘Paired Cylinders’ throughout the article.

Keeping the above info in mind, as you test the ignition system, will help you to easily diagnose the root cause of the misfire. Now, don't let all of this info intimidate you, the article should walk you thru' the whole testing process without too much difficulty.



Ford Vehicles:

  • Crown Victoria
    • 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002
  • E150, E250, E350
    • 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005
  • Expedition
    • 1997, 1998, 1999, 2000, 2001, 2002
  • Explorer (4.6L)
    • 2002, 2003, 2004, 2005

Ford Vehicles:

  • F150, F250, F350
    • 1997, 1998, 1999, 2000, 2001, 2002, 2003
  • Mustang GT & Cobra
    • 1996, 1997, 1998
  • Thunderbird
    • 1995, 1996, 1997

Lincoln Vehicles:

  • Navigator
    • 1998, 1999

Lincoln Vehicles:

  • Town Car
    • 1996, 1997, 1998, 1999, 2000

Mercury Vehicles:

  • Cougar
    • 1995, 1996, 1997
  • Grand Marquis
    • 1995, 1996, 1997, 1998, 1999, 2000, 2001
  • Mountaineer (4.6L)
    • 2000, 2001, 2002

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