A 4.6/5.4/6.8 2v Modular engine COP ignition coil
1991-1997 Town Car and 1992-1997 Crown Victoria and Grand Marquis have a waste-spark ignition system. This was the first all-electronic distributor-less ignition system for the panther platform with it's new 4.6l Modular engine.
The waste-spark EDIS uses two main coil packs, mounted at the front of the engine, with spark plug wires from the packs to each cylinder. Each of these packs contain two primary coils each igniting 2 cylinders/spark plugs.
As the name denotes, because of the paired cylinder firing one of the sparks is 'wasted' on the non-firing cylinder (which is on it's exhaust stroke).
The two coil packs are powered constant w/ ignition, with the primary coils being triggered via ground pulse from the PCM. THere are 4 total ground triggers, one for each coil in each coil pack, and each one for two cylinders.
1998 to current Crown Victoria, Grand Marquis, Town Car, and the '03-'04 Marauder use an ignition system called coil-on/near-plug. This system uses a separate ignition coil for each cylinder, allowing full individual spark control of each cylinder by the power train control module.
The ignition coils are mounted to the intake manifold, directly above each plug and use a small rubber boot and spring to connect to the plug. The electrical connection to the engine harness is a small two pin connector. Voltage is supplied constant w/ ignition, with the ground for each coil being triggered by the PCM.
With some work, we can retrofit the '98+ style COPs to our '91/'92-'97s - but with one main difference. Unlike the factory '98+ system, ours will remain waste-spark EDIS. So, we need to fire two of the new COPs at the same time using the existing PCM ground triggers.
The advantage is a cleaner engine bay appearance and more clearance around the engine.
But, a draw back is the -'97 plug wire/coil pack setup is far more resilient to moisture-induced misfires than the '98+
You won't notice any power increase from this modification, other than being new(er) coils versus old. This is really just for aesthetics and to gain some clearance.
As far as which COPs you should use - I recommend using Genuine OE Motorcraft coils. These are the same for all 4.6/5.4/6.8 modular 2v engines. DG508 is the current Motorcraft part number.
I am starting out with mounting, because there is a catch with this and it may shy many of you from the entire project.
The COPs are designed to bolt to the intake manifold using a single M6x20mm bolt. However, only the 1998+ 4.6l 2v intakes have the provisions/mount for the COPs.
So, if you want to use OEM or aftermarket factory-style COPS you need an intakem manifold with these provisions. For '96-'97, that means a '98-'00 nPI intake manifold. If your manifold has already been replaced for the coolant crossover issue, you're in luck. All the updated aluminum crossover manifolds have the COP provisions - so you're good to go.
'91/'92-'97 have it a little tougher. A complete '96-'97 style intake/EGR/fuel rail conversion to use a '96-'00 style nPi intake w/ COP provisions, and everything entailed with that. That said, it's not practical.
But, you're not completely out of luck. This applies to the '96-'97 guys who are (and want to stick with) their factory non-COP manifolds as well.
A few aftermarket vendors are now selling a 4.6l 2v COP which uses no mounting, it simply locks to the plug and plugs into the same connection as the factory. WeaponX is one of a few companies selling these. So, that would be the easiest way for '92-'95 to go ahead with this conversion without EXTENSIVE modifications.
This is surprisingly simple to wire up.
First off, you want to pick up at least 8 COP connectors of a salvage yard car - or order new pigtails from Ford. Do NOT attempt to use a factory COP harness whole, it won't work, as you will find below.
Basically, what we will be doing is wiring the COPs for the existing coil pack cylinder pairs in SERIES. This will fire both COPs for the corresponding cylinder pair using the existing PCM ground triggers at the coil pack connectors.
Most of you are probably thinking - why in series? Wouldn't it be better in parallel?
Well, actually, you're right. Parallel would be better as then if there is an issue with one COP it won't knock out the other COP it is paired with. Both COPs will also have full power when triggered. But, we cannot wire them like this. The PCM ground triggers cannot support enough amperage to ground BOTH COPs when wired in parallel.
That said, DON'T WIRE THEM IN PARALLEL! Trust me, the car will not start or run if you do so - I tested it myself. You could even damage the PCM by doing so.
So, here's a wiring diagram of how we will wire them in series:
So, on the right side coil pack wiring we see the cylinder 1 and 6 pair wired to the COPs in series. For the diagram, I used a green wire - but you can use whatever color you fancy.
Also on the RH coil is the cylinder 3 and 5 pair, I used blue for the diagram.
On the left coil cylinder 2 and cylinder 8 are show with a yellow wire. Cylinder 4 and 7 with orange.
For all cylinder pairs - in the diagram the coil seeing the hot/B+ side of the series pair has a red wire to the connector's Red/Light Green B+ wire. This is to be wired to the COP connectors "B+" labeled pin, which will have a Red/light green wire if using salvage pigtails.
All wiring should be at least 14-16awg.
All of your splices to the COP connector pigtails should be soldered and covered with adhesive-lined heat shrink tubing. The entire harness should be wrapped with wire loom then tapped up with electrical tape.
Splices to the stock coil pack wiring can be soldered for a permanent install - but I recommend using connectors instead so the harness can be removed if needed. Three-pin "Weather-pak" style connectors would be perfect for this.
You can leave the stock coil pack connectors wired in as well if you please. If so, make sure to cover it well to prevent moisture from corroding the terminals.
Take your time assembling the harness for a clean installation. I made mine on a bench, and measured the distance from plug to plug for a factory fit. But you can make it in-car if you prefer.
Make sure to leave PLENTY of slack at the back of the harness, where it crosses over between sides. Also take care routing the harness along the back to keep it away from EGR heat.
Additional info making the harness;
Here are some new pictures and info for the conversion harness assembly and how to use sealed weather-pack connectors for the connection to stock harness
The COP connector pigtails;
If using salvage pigtails like I did, you can match up the wire colors/pigtails to the corresponding cylinder on the 98+ COP system.
Those tabs are on the BOTTOM of each COP connector, so these labels won't be seen with the harness installed and can be left on.
Harness fabrication -
First you will want to plan the layout of your harness.
I used 14 awg wire for the ground trigger wires too and between COP pigtails, and 12 AWG for the switched ignition power feed. this is WAY overkill, but I figured what the hell :D
16awg would be sufficient. Since the factory groudn trigger wires are all tan base color, I used tan wire which I made color coding stripes on for the cylinder pairs.
I knew I also needed to connect to the radio noise capacitors at the front of the engine and I am also using the ignition circuit for a switched feed to a relay (for my intercooler fans/pump) so I integrated this to the harness.
You don't want your car shutting down in the middle of the road because of a loose connection, so I recommend soldering all the pigtails and using adhesive-lined heatshrink tubing - this has a thin coating of adhesive on the inner wall that will melt as the tubing shrinks, providing even more strain relief and sealing the connection from moisture.
Ford uses this type of heatshrink tubing for virtually every splice throughout your car.
Here is mine with the wiring complete, I have also provided the measurements I used and recommend for a good fit;
(click for full size)
The original COP conversion harness I made last year had 18" around the back of the manifold. Although this seemed plenty mocking it up off the car, the fit was a little tighter than I wanted, so this time I made it longer for more room.
Another change I made this time was to use heatshrink at the base of each pigtail to keep the wires neater and make taping up the harness easier.
Terminating the harness ends -
I like keeping the harness removable from the stock engine harness if needed, so inline connectors are needed.
I decided to use 3 pin flat weather-pack sealed connectors. These have been around for years, made by Delphi (formerly Packard-Electric) originally for GM vehicles. They are easy to put together and extremely resilient to vibration, heat and the elements - making them an ideal choice.
Here are the male and female connectors with the pins and seals lined up;
Note, those blue seals and the terminals pictured are for the thicker wiring I was using - size to your application!
The factory coil pack wiring appears to use 16 awg for the Red/LG switched B+ and 18awg for ground triggers. I used 14-16 awg terminals and seals for all of the factory wires
Assembling the connectors is easy. First, strip back the insulation of each wire 1/4" and slide one of the weather seals on each wire with the ribbed side toward harness
Next, position the terminal for the connector you are putting together over the seal and wiring as shown;
Pinching the seal tabs slightly will keep the terminal from falling off.
Now you have to crimp the terminal. Delphi sells a special tool for this that crimps both the seal and wire at once, but it runs over $100 which probably isn't worth it for the occasional weather-pack connector assembly :tongue:
So, instead I used a basic uninsulated terminal barrel crimp tool. It was able to make a *decent* crimp, still very secure;
To make absolutely certain this wouldn't fall apart, I decided to solder over the crimped connections as well.
Note, I'm sure this is not recommended by Delphi and is completely optional. If you build up the solder too high you won't be able to lock the terminal in.
You can see the wire insulation melted some out of the crimped seal from the heat when soldering. The seal is made from silicone so it was unaffected. This connection is rock solid.
With the terminal attached you can slide them into the connector bodies, aka "towers" and "shrouds" for weather-pack connectors;
When all the terminals are locked in place, the black covers can be locked into position to secure the wires completing the connector assembly;
A view of the opposite side, note the color coding so the two tan wires won't be mixed up;
Don't forget you also need to do this using the opposite gender connectors / terminals onto the factory wiring for the harness to connect to!
If desired you can also use male on one end and female connector on the other of your harness and matched to the factory wiring so it can *only* be installed the right way and not reversed. I did not bother with this.
With the wiring completed and the connectors installed, you can put wire loom over the entire harness, leaving ~1.5-2" from the connectors - then wrap the whole thing up in tape for a factory appearance;
Something I didn't think of before installing mine - you could also wrap the back section with foil tape of insulating sleeve to protect the harness from heat from the EGR tube. However, your EGR tube should have the braided insulated covering over it, so this is of little concern (note the factory harnesses passing behind manifold are not insulated either)
Route the completed harness around the manifold and existing harnesses for a good fit. Nylon zip-ties may be useful to keep it in place, disconnecting some of the fuel injectors will make life easier too (be careful that the little injector connector seals don't fall out, they are very loose)
Radio Noise capacitors:
Thought I should mention this as well. Mine are still wired in with the stock wiring, which I cut AFTER the splice to the capacitors.
I recommend you retain these to prevent any unwanted electrical noise feedback to the sound system. Since the coil packs will be gone you need to mount them elsewhere. I enlarged the holes on the metal mounting tab for each and mounted them to one of the existing timing cover bosses where the coil pack brackets were on each side, using the same bolts. Works great and keeps them tucked tight to the engine.
I've logged nearly a thousand miles so far on this conversion, with forced induction, without issue. The engine bay looks much cleaner without all the plug wires.
BTW, make sure to use plenty of dielectric grease on those COP boots - all around the seal to the head and some inside the tip to plug as well.
Picture of my COPs and harness installed on RH side:
Have fun! :biggrin:
Email me at dRock96Marquis@crownvic.net
Page last updated: 7-20-2008