2 years ago at 80K miles I changed the plugs, boots/resistors and wires. I found 3 resistors in powder and the part of the coil the holds them in place eaten away from the coil arcing when the resistor failed. I used electrical tape on two of them and a small piece of shrink tubing on one to hold them upright. This spring at 95K when I was servicing the truck before it was put in storage I removed the three coils and the ones with the tape were starting to come apart but the one with shrink tube looked fine. I removed all the coils and boots cleaned them all and shrink tubed all of them. I found a couple of the other ones that looked like the resister was no longer standing up because the coil was getting eaten away. This time when I installed the shrink tubing I put it all the way to the top of the register to maybe stop some of the arcing around the resister.
Now the truck is on the road pulling our trailer and as usual into a 20+ mph head wind yesterday and I can really tell the difference in the way it runs, pulls and holds the gears pulling the trailer so it's my belief that the resisters health is very important to the way the 6.2 runs and pulls. This is how it was when new pulling the same trailer. The next time I change the boots I will use shrink tubing and make a tool to clean the contact in the coil. I also think the resisters are a weak point in a otherwise great motor and will keep an eye on them from now on.

Denny

 

Always wondered if you can just eliminate the resistor, and are they just used for noise suppression, or static interference for the electronics?

 

They are used to match the resistance of the wires so both plugs fire at the same time.

Denny

 

Ok, I’m not wondering any further ​​​​​!

Thanks for your explanation.

 

The resistor ("Pill") is there to provide correction for stringent EMI/RFI requirements - Officially referred to as "ElectroMagnetic Compatibility (EMC) under ISO 7637. This series covers electrical disturbances from conduction and coupling, while the ISO 11451 and ISO 11452 series detail test methods for vehicle and component immunity to radiated and conducted electromagnetic energy, respectively.

Specifically:
- "A Resistor in Isolation" (this particular instance): A resistor by itself does not inherently cause a time delay in the sense of storing energy or delaying signal propagation. It simply limits current flow and drops voltage according to Ohm’s Law (V = IR).
However, its presence can affect timing indirectly by altering the circuit's behavior - the resistor can "Shape" the spark by reducing voltage signal rise/decay at the plug making for a more uniform ignition spark - assuming EMI/RFI was not Ford's specific rationale.

- The "Pills" are approximately 1.2K Ohms, the wires are 5K Ohms or more new (Used wires in my vehicle ranged from 6-8K Ohms), so there is no "resistance matching".

The "Pills" can be left out, if the spring is "modified" to fill the gap but this is NOTadvisable as an electronically controlled powertrain is especially susceptible to EMI/RFI "miscuings" and potential damage to circuits.

I find @rvpuller's fix to be amazing in it's simplicity and it's ability to eliminate potential arcing AROUND the pill - which I believe is what happens just prior to the pill being turned to dust, and the internal fin erosion which can be seen in abused coil packs.

I might have used this as all my coils were "functional", but then I couldn't test my theory.

Extra Credit:
See

You Tube

 

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I quoted what I think is what you were saying, but please correct me if I am wrong. Thanks

 

Thanks rv! Great information and I second the power difference while towing! I too had similar issues at about 80K and replaced all coils! I am planning to replace boots much sooner next time!

 

Holy Copy/Pasta Batman!
Thanks!

 

Been a little slow getting back to this but we are on the road and I can tell you my fix made a world of difference in towing performance and I think a little gain in mileage. I will be changing my boots and pills every 40K.

I'm wondering what the resistance is from the top of the pill to the end of the spring. In all my experience with caps and resistors I haven't seen a resistor fail that way but it sure looks like what I've saw when a start Cap failed. But with the pulsing not constant high voltage we are dealing with it's hard to say what it is but I know when they are working right it makes a big difference when working the motor hard. There are also a lot of materials out there that will cause a delay when a current is past through them. They are cheap maintenance items so mine will be changed often.

Denny

 

Let me know how you guys are cleaning the contact area of corrosion in the coil. Mechanically, I can't get much in there to scrape it clean so I think MAF cleaner followed by the air compressor is likely the best I can do.

 

What I did was take a small flat blade screwdriver and scrape it off. Still thinking of a better way 🤔
Denny

 

I would just take a .44mag cleaning brush, and chuck it up in a drill?

 

I was thinking of using the small wire brush that I clean my paint gun with.

Denny

 

Been having problems with the truck and one of them was a bad coil on #2 cylinder. I bought a coil from O'Reilly's Auto Parts and you can see one of the photos it has a different setup for the pill. Now that I had #4 intake valve spring replaced and a new MAF sensor the truck runs like new. The broken spring never made a noise so I didn't think that was a problem but I was wrong. The MAF was my fault because I blew out the air box with air and contaminated the sensor. I'm down south so I ended up bringing it to a shop, they never found the spring until they did a compression test and they were all 175 except for 0 on #4. Had a lot of codes.
Denny

 

Thanks! I am going to look into this! I got the Standard wire and boot set from Rockauto and they included original style springs. Rockauto also shows the same Standard coil part number here? 🤔. Thanks again for sharing! Herman