• NAXJA is having its 18th annual March Membership Drive!!!
    Everyone who joins or renews during March will be entered into a drawing!
    More Information - Join/Renew
  • Welcome to the new NAXJA Forum! If your password does not work, please use "Forgot your password?" link on the log-in page. Please feel free to reach out to [email protected] if we can provide any assistance.

Replacing the 00+ coil rail with aftermarket coils

I've done it. The end goal is to stretch the factory connector. The patch connecter has to be flipped to make a direct pass through.

Its easy and I prefer this to making brackets and I hate the factory coil pack.
 
My understanding is you don't have to flip the connector if cutting and extending the original wiring harness -- just extend as is

You flip if you use the $40 adapter because of how the adapter is made

I have not done this yet, someone please confirm...
That was what I was inferring ... The flipping is because the harness used is a crossover harness.

Sent from my SM-G930W8 using Tapatalk
 
That's correct... if using the additional harness (so you don't have to cut the factory harness/plug) you do have to flip the plug to the Viper Coil. Plus there's just not much room to cut the OE plug and then wire up additional wiring, it can be done, but it's much easier to extend and flip the adapter to any length wanted and then just plug them in. :)
 
Bringing this back once again

Since photo bucket destroyed this thread I need a little help on the firing order -- In what order does the viper coil fire?

I've finally made my bracket and want to hook this up over the weekend -- Can't see the firing order pictures anymore -- Repost?

Thanks, Jer
 
Ok -- found this on another forum -- Does this look right?




vipercoil.jpg
 
Getting a parts list together to do this swap on my 00 XJ, couple quick questions:

1. Will the Screamin' Demon coil (DUI-31729) for the 02 viper work? It has a 45k voltage.

2. What spark plugs are you using and with what size gap?
 
The screamin demon coil will work. That was one of the upgrades I was going to do in the future, but haven't gotten around to it yet.

I'm running colder than stock NGK plugs. Can't recall the part number, but gapped to .040"
 
Good to know about the Screamin Demon coil... just for future reference if needed. I'd also think if you're going w/the higher output Coil then a 1 range colder plug would be feasible. I run the standard NGK plugs and I think they're gaped to the 0.035" NGK setting. The larger gap would likely work if you're upping the Coil. I've not done that on a Jeep 4.0 but it was common on sports cars and Mustangs I've had in the past to do that same thing.

Let us know how it goes.

Oh, and sorry about Photobucket killing all the pics... they can kiss my @ss if they think I'm paying them to host photos...
 
Has anybody tried the 3.8 JK coil?
 
Nope!
17610_610X_PG.htm
 
It's the same Viper coil some are already using!
 
Interesting! I wonder if the firing order on those will work on the XJ 4.0?? That would make sourcing the ignition parts a LOT easier to do this swap.

For what it's worth, coils don't have a firing order, that's determined by the ECU wiring. Either way you can either switch 2 driver wires or just move the spark plug wires!
 
It's the same Viper coil some are already using!

I have to question why? Why do you need that kit if it's the same coil as the viper coil -- the viper coil is like $30 on rock auto

That means you are paying like $150 for wires -- Why?

Am I missing something?


Reading that makes me think I'm running the wrong spark plugs --at least I'm running the wrong plug gap -- that quadratech link says .065 plug gap -- I think I'm at .035 -- not sure what plugs I have in at the moment
 
Last edited:
I have to question why? Why do you need that kit if it's the same coil as the viper coil -- the viper coil is like $30 on rock auto

That means you are paying like $150 for wires -- Why?

Am I missing something?


Reading that makes me think I'm running the wrong spark plugs --at least I'm running the wrong plug gap -- that quadratech link says .065 plug gap -- I think I'm at .035 -- not sure what plugs I have in at the moment

It was just a example showing that the JK uses the same coil. I ordered a stock(JK) one yesterday along with the harness adapter. Between measuring the resistance and the pin-out, I will figure what to do with it then. See my other thread..... https://naxja.org/forum/showthread.php?t=1148702
 
Back
Top