Bronco Forum - Full Size Ford Bronco Forum banner
1 - 20 of 27 Posts

MidlifeCrisisUndrWay
Joined
2,029 Posts
Discussion Starter · #1 ·
Just finished an ignition maintenance update/upgrade (after 5 years):
New sparkplug wires
New cap and rotor
New (proper) black ICM
Re-gapped sparkplugs
Checked/confirmed timing

WHEN SHOULD THE IGNITION COIL BE REPLACED? 馃
 

Registered
95 5.8L MAF XLT, Hedman Shorties/MF SS Y & Muff, E4OD, Man hubs, KYB Quads, 31x10.5x15, 304K miles
Joined
1,456 Posts
Unless you like spending money then replace it whenever it looks dirty!!!!馃ぃ
 

MidlifeCrisisUndrWay
Joined
2,029 Posts
Discussion Starter · #8 ·
would avoid MSD if you change it. they are not what they used to be. i been using Accel but had one of them fail even
I was looking at NGK.
 

Premium Member
Joined
422 Posts
Go with Motorcraft. All OEM ignition parts can still be found on RockAuto and Summit.
 
  • Like
Reactions: BroncMom and miesk5

MidlifeCrisisUndrWay
Joined
2,029 Posts
Discussion Starter · #11 ·
Go with Motorcraft. All OEM ignition parts can still be found on RockAuto and Summit.
How come?
I've heard/read good and bad (more bad) about Motorcraft OEM parts.
IMHO; that goes for today's OEM parts in general.

25+ years ago? I would agree.
Today; I'm much more skeptical.
 

Super Moderator
Joined
29,800 Posts
Yo
High Quality Motorcraft TFI Ignition Coil Attributes
Source: by SeattleFSB (Seattle FSB) @ MSD 8227 coil problems
Many Bronco owners shop for an ignition coil by looking for the highest voltage available. But I venture to say that there is much more to look for in achieving both a quality ignition system and saving money in the long run.

For clarification, it takes approximately 10-14,000 volts to initiate the spark across the OEM spark plug gap. After the initial arc, the voltage required to sustain the arc is much less and drops off significantly. So while you may have a 48,000v coil you can't actually get that across the plug. The extra power becomes reserve voltage which compensates for worn plugs, increasing resistance in wires and carbon fouling. This increased stress can require an additional 1-5000 volts.
Fact is a higher voltage coil does not work any better, it just lasts longer due to having a higher reserve reducing heat. You cannot push more than 20,000 volts across a spark plug without bad things happening. If you were to try you would see arcing down the side of the plug, across carbon buildups at the electrode end and out any weak points in the wire insulation and connections.

The bottom line is the ideal coil output required for normal applications is about 30,000 volts. So no, your coil does not need to be 48,000v for proper ignition. The benefit would be in having enough reserve to compensate for high resistance due to a worn or altered ignition system.

This is why the Sixlitre Tune recommends a 48,000v coil and larger spark plug wires 鈥 to compensate for a substantial increase in resistance from larger than specified spark plug gaps. You are adding resistance as the spark attempts to reach ground. This in turn causes the plug wires to break down and decreases the service life of the rotor, distributor cap, spark plugs and increases the chance of spark scatter within the Distributor Cap.

Think about it, you are setting your spark plugs at a maximum gap even before wear. The higher voltage coil does not reduce stress and wear on your ignition system; it only compensates within a larger margin and then ultimately becomes dependent upon the quality of construction for survival. When opening up your spark plug gap from factory specifications you must be prepared to check your secondary ignition system annually, as opposed to about 40,000 miles with a stock vehicle, or risk performance decreases down the road.


With that being said, IMHO the Motorcraft DG470 TFI Coil is one of the most dependable 48,000v TFI Coils on the market. This is largely due to the quality in design, testing and construction. I have personally had many dependability issues with other imported TFI Coils, such as MSD. Where a Motorcraft Coil has lasted 15 years, I have went through three MSD coils in five years. Your purchase of a TFI Coil should not be totally dependent upon the voltage, but strong consideration should also be made regarding the contruction attributes listed below:


Motorcraft TFI Ignition Coil Attributes
Insulation - Multiple coats on the primary and secondary windings to ensure no internal arcing
Radio-Frequency Interference (RFI) Suppression - Minimize electronic noise
Magnets - Hold strength for the coil to maintain proper energy output
Steel - Used in the lamination stack to ensure a consistent magnetic field needed to develop the required voltage
Coil Housing - Engineered to withstand extremes in temperature without cracking


Low Quality TFI Ignition Coil Potential Issues
Rough Running Engine or Misfires - Causing Check Engine Light
Fuel Economy and Power Decrease 鈥 Costs money and performance
Radio Frequency Interference 鈥 Affects radio, EEC, sensors, cell phone
Pre-Ignition and Detonation 鈥 Can cause engine damage
Weak Voltage Output 鈥 Can cause increase tailpipe emissions..."
 

MidlifeCrisisUndrWay
Joined
2,029 Posts
Discussion Starter · #13 ·
Yo
With that being said, IMHO the Motorcraft DG470 TFI Coil is one of the most dependable 48,000v TFI Coils on the market. This is largely due to the quality in design, testing and construction. I have personally had many dependability issues with other imported TFI Coils, such as MSD. Where a Motorcraft Coil has lasted 15 years, I have went through three MSD coils in five years. Your purchase of a TFI Coil should not be totally dependent upon the voltage, but strong consideration should also be made regarding the contruction attributes listed below:

Motorcraft TFI Ignition Coil Attributes
Insulation - Multiple coats on the primary and secondary windings to ensure no internal arcing
Radio-Frequency Interference (RFI) Suppression - Minimize electronic noise
Magnets - Hold strength for the coil to maintain proper energy output
Steel - Used in the lamination stack to ensure a consistent magnetic field needed to develop the required voltage
Coil Housing - Engineered to withstand extremes in temperature without cracking

Low Quality TFI Ignition Coil Potential Issues
Rough Running Engine or Misfires - Causing Check Engine Light
Fuel Economy and Power Decrease 鈥 Costs money and performance
Radio Frequency Interference 鈥 Affects radio, EEC, sensors, cell phone
Pre-Ignition and Detonation 鈥 Can cause engine damage
Weak Voltage Output 鈥 Can cause increase tailpipe emissions..."
馃

Even today, eh?
 
  • Like
Reactions: miesk5

Super Moderator
Joined
29,800 Posts
Our 96, bought new, still has it's original MC coil.
 

MidlifeCrisisUndrWay
Joined
2,029 Posts
Discussion Starter · #15 ·
Our 96, bought new, still has it's original MC coil.
So it's a 1995/6 manufactured coil and not manufactured in 2020/2021, correct?
That's my concern and point of the thread; pre-2000 manufactured OEM parts vs current manufactured OEM parts.
 
  • Like
Reactions: miesk5

Super Moderator
Joined
29,800 Posts
So it's a 1995/6 manufactured coil and not manufactured in 2020/2021, correct?
That's my concern and point of the thread; pre-2000 manufactured OEM parts vs current manufactured OEM parts.
Yo,
CORRECT!
 
  • Like
Reactions: CDA 455

MidlifeCrisisUndrWay
Joined
2,029 Posts
Discussion Starter · #17 ·
Yo,
CORRECT!
5 years ago I crawled out from under a rock; vehicle maintenance-wise.馃槅馃槵

I had a shop do a ignition diagnosis.
One of the thing they did was replace the factory-original coil.馃檨
The problem turned out to be the distributor.馃槧馃檮

2.5 years ago I replaced the starter with an OEM one.
6 months in, it started acting up.
I've been milking/nursing it ever since.
I'll probably replace it this Summer with an after market high quality performance one.

Bottom line:
I'm learning that this isn't pre-1995 anyone; manufacturing quality has changed greatly in the last 25 years.
 

Registered
95 5.8L MAF XLT, Hedman Shorties/MF SS Y & Muff, E4OD, Man hubs, KYB Quads, 31x10.5x15, 304K miles
Joined
1,456 Posts
Yup it's a "CRAP" Shoot these days with parts.... Lifetime warranties help but who likes doing things more than "Once"....
 

Man of endless projects
Joined
9,969 Posts
If it were me I'd say Motorcraft is the top choice even if quality has dropped over the years. They all have unfortunately

Accel would be my second choice

I am actually using a Holley Sniper coil on my 96. It's basically just a TFI coil but has a nice little bracket for relocation and included a pigtail. I need it to relocate with aftermarket intake manifold. No idea how long it will last but it wasn't that expensive and I can probably replace it with another TFI coil in a pinch
 

Super Moderator
Joined
29,800 Posts
Yo,
Keep your oem coil in place and save your new one in glove compartment until needed.
 
1 - 20 of 27 Posts
Top