Why The HEI Spark Tester?
If you have read any of my ignition system test articles, you'll notice that I'm always writing the article around the HEI spark tester. Why? Well for several reasons and they are:
- 1
The HEI spark tester is accurate and this will save you money making your diagnostic reach the right conclusion and this will keep you from replacing good parts.
How? Well, no other spark tester stress tests the ignition coil or the spark plug wire (high tension wire) like the HEI spark tester. The stress test that the HEI spark tester puts the ignition coil under, produces a spark or a no spark test result you can take to the bank. - 2
The HEI spark tester does not cost an arm and a leg. It usually retails for around 10 to 14 US dollars (don't have an HEI spark tester? Need to buy one? You can buy it here: OTC 6589 Electronic Ignition Spark Tester).
- 3
You don't have to interpret the color of the spark on the HEI spark tester. On some spark testers, it's suggested that you have to interpret the color of the spark (which is total BS in the first place since the color of the spark has nothing to do with anything).
If the HEI spark tester sparks, the spark is present and strong enough. If it doesn't spark, then you have a bonafide no spark result you can trust. - 4
In the long years I've spent working as a diagnostic automotive technician, I have used a lot of different tools to test for spark and from personal experience I know it works and I can therefore recommend it to you.
I Have Misfire Codes
If you have a scan tool (or a code reader) and have retrieved specific misfire codes, then the most important thing you need to do is identify which cylinder or cylinders are the ones that the misfire codes are accusing of misfiring.
This is pretty easy, and since it's key to using this test article, I'll show you how in this section.
OK, this is what you need to do to get this show on the road:
- 1
The first thing is to use the illustration of the 4.6L/5.4L engine (in the image viewer) to identify the cylinder or cylinders that the misfire code is accusing of misfiring.
- 2
Next, you need to make sure that the COP coil is sparking. This requires testing the ignition coil with or without a spark tester. So choose from one of the following DIAGNOSTIC TEST OPTIONs below:
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.
I Have NO Misfire Codes
If you have NO misfire codes but you do have a bonafide misfire condition (and this happens A LOT!), you can still use the info in this article, the most important thing you need to do is identify which cylinder or cylinders are misfiring.
To find out, you're gonna' have to test all of the spark plug wires for spark or do a cylinder balance test by disconnecting one fuel injector at a time.
I have written step-by-step instructions on this cylinder balance for the 4.6L and 5.4L Ford engines with C.O.P ignition coils but the instructions will apply to your specific 4.6L with coil pack ignition. You can find it here: TEST 5: Cylinder Balance Test (found at: easyautodiagnostics.com).
OK, once you have found out which cylinders are dead:
- 1
Using the illustration of the 4.6L/5.4L engine (in the image viewer), identify the cylinder or cylinders that are dead (misfiring).
- 2
Next, you now need to test the ‘dead’ cylinder's COP coil for spark. You can do this with a spark tester or without one by choosing one of the following DIAGNOSTIC TEST OPTION's below:
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.
Related Test Articles
I've written several more tutorials that may be of interest to you. These are specific Ford car (pick up, van) tutorials you can find here: Ford 4.6L, 5.4L Index Of Articles.
Here's a sample of the articles you'll find in the index:
- How To Test The Fuel Pump -No Start Test (Ford 4.6L, 5.4L).
- How To Diagnose Misfire Codes P0300-P0308 (Ford 4.6L, 5.4L).
- How To Test Engine Compression (Ford 4.6L, 5.4L).
- How To Test The Fuel Injectors (Ford 4.6L, 5.4L).
- How To Clean The Ford MAF Sensor (Ford 4.2L, 4.6L, 5.4L) (at: easyautodiagnostics.com).
If this info saved the day, buy me a beer!
