Coil-on-Plug Misfire Tests
4.6L, 5.4L Ford
-Part I-


This article will help you to diagnose a Misfire Condition lighting up the Check Engine Light on your 4.6L or 5.4L Ford vehicle with the following Misfire Diagnostic Trouble Codes: P0301, P0302, P0303, P0304, P0305, P0306, P0308.

More specifically, this article is designed to help you troubleshoot a BAD Coil-on-Plug (COP) Ignition Coil with step-by-step testing instructions.

Alright, to help you navigate this article a little easier, here are its contents at a quick glance:

Important Tips and Suggestions

IMPORTANT: Before you start, read the following first:

TIP 1:   The very first thing you have to do, before you start testing with the info in this article, is to find out which Cylinder or Cylinders are Misfiring. Please read the following sections: I Have a Misfire Code(s) or I Have NO Misfire Code(s) before jumping into COP COIL TEST 1.

TIP 2:   Most of the testing, that you’ll be doing, is done with the Engine cranking... so be careful and stay alert. My biggest suggestion to you is to have your helper wait outside the vehicle as you set up the test to avoid having him or her crank the Engine accidentally.

TIP 3:   You’ll notice that the photos and the testing instructions call for an HEI Spark Tester. If you don’t have one, you can use any other type of Spark Tester (although the results may not be as accurate). If you want to know why I recommend the HEI Spark Tester, go to section: Why the HEI Spark Tester..

BEGIN HERE

There are several ways to find out if the COP Ignition Coil on your Ford 4.6L or 5.4L is BAD or not. One is using a Spark Tester and is the most accurate way of testing for a BAD Coil-on-Plug (COP) Ignition Coil. The other is without one and requires that you swap the some COP Coils to find out. I’m gonna’ explain both in this article.

Now, you don’t have to read the entire article to use the info presented here but, I suggest you do. To help you effectively use this test article, read the following CASES and follow the one that applies to your specific testing situation/ needs.

If you haven’t read the sections: I Have a Misfire Codes or I Have NO Misfire Codes, please do so now.

DIAGNOSTIC TEST OPTION 1:   You have a Spark Tester and plan to troubleshoot the COP Coils with it, start at COP COIL TEST 1.

DIAGNOSTIC TEST OPTION 2:   You don’t have a Spark Tester, start here: COP COIL TEST 2.



More Ford 4.6L, 5.4L Articles:



MAF Sensor Test


EGR Valve Test


Thermostat Test


Troubleshooting P0171, P0174

Applies To:

 

Ford Vehicles:

  • Crown Victoria
    • 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005
  • E150, E250, E350
    • 1997, 1998, 1999, 2000, 2001, 2002
  • Expedition
    • 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009

Ford Vehicles:

  • Explorer (4.6L)
    • 2002, 2003, 2004, 2005
  • F150, F250
    • 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008
  • Mustang (GT & Cobra)
    • 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005

Ford Vehicles:

  • Thunderbird
    • 1995, 1996, 1997

Lincoln Vehicles:

  • Aviator
    • 2003, 2004, 2005
  • Mark VIII
    • 1995, 1996, 1997, 1998

Lincoln Vehicles:

  • Navigator
    • 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
  • Town Car
    • 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005

Mercury Vehicles:

  • Cougar
    • 1995, 1996, 1997
  • Grand Marquis
    • 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005
  • Mountaineer (4.6L)
    • 2002, 2003, 2004, 2005