Good bye coil rail.

[SilverXJ]

I wired it the same as above - looking at the top with the plug to the right

Its mounted and wired in the same manner as my install then (aside from flipping 3&4 on the same coil)?

[bryweb]

Its currently not even mounted - just laying on top of the of the heater hoses, and yep.... only difference is 3&4 spark plug wires are flipped from image below., but I have no doubt it would work the other way.... I was just being too lazy at the time to switch spark plug wires around to reach and understood that it should work either way.

Jeep started right up, engine revved with no problem, and I have no doubt it would drive fine. (waiting to bleed brakes, add T/C fluid, add axle fluid, etc.)

I had a miss and (2) codes with the original xj factory coil pack (coil a failure and coil b failure), switched to the Dodge (non viper) coil with 56032520AB stamped on the back and some used Caravan plug wires, shaved connector on the coil so I could slide the wire loom connector on (not extended yet), and it started right up and ran great. I was surprised it worked after people here had problems with AIRTEX # 5C1432 which cross references to the number I had..... I just figured I had nothing to lose since I had that coil to try.

Now I just need to determine if there is any advantage to switch over to the Viper Coil (Hotter spark or ????)



Bryan

[bryweb]

PS: I just went to the garage and flipped spark plug wires 3 & 4 to match your diagram above and it ran just the same (which is good).

Originally I wired by mistake like this. (3 & 4 flipped) - connector is to the right.



Then I flipped the coil upside down and took a picture of the part # (it was much easier to read in person than in the photo, but you can read the part # in the photo)



Just thought I would pass along my experience.

Thanks,

Bryan

[SilverXJ]

You two people with the 99 WJs. I believe I have found your problem.

The 99 WJ had a coil rail and plug wiring different from every other year. My previous look on Rockauto showed a coil rail for all years. However, after taking a closer look at just 99 they had one coil rail listed for all years. The others were just for 99.

I finally found a 99 FSM and compared the coil pin out wiring between 04 and 99. The difference is the coil plug wiring. The wiring is reversed.

Here are your two options to make the Viper or Caravan coil work.
1) Use this adapter harness: Airtex/wells 1P2041(OEM: 68061344AA) which will adapt the 99 harness to later coil rails and the Viper coil pack.
2) Cut the plug off (or de-pin it) the 99 WJ harness, and reverse the wiring pin for pin on the plug. Eg. pin 1 goes where pine 4 is, pin 2 goes where pin 3 is, pin 3 goes where pin 2 is and pin pin 4 goes to pin 1. Another way to look it is lay the plug flat, cut it and flip it 180*.

Now if you do that the coil pack should work. If you need to go back to the coil rail you either change the wire modification or use a coil rail from any other jeep with the coil rail, but not a 99 WJ.

I may draw something up later for the harness modification.

[SilverXJ]

This is what you need to do:


I'm hoping that the wire order is correct because even the FSM is screwy on this. But that is what the 99 WJ adapter harness does to use the same rail as other coil rail vehicles.

[darkcorp]

SilverXJ, you are great as always. Thank you very much, I've already been thinking that I waste money on Airtex coil. Now there is hope that it will work properly.
I'd love to translate your coil mod to Russian to post in my lokal forum if you don't mind.

[SilverXJ]

SilverXJ, you are great as always. Thank you very much, I've already been thinking that I waste money on Airtex coil. Now there is hope that it will work properly.

It was bugging me why it wouldn't work so I had to make a few contacts and sort it out. Let me know how it works for you as I can't test it myself.

I'd love to translate your coil mod to Russian to post in my lokal forum if you don't mind.

I don't usually like people duplicating my work, but since its for translation purposes go ahead.

[bugaboots]

Just stumbled upon this, think i might go this rout if i ever have issues with my rail. That or just do it next time i have to pull the rail off.

[joshbaker]

sorry i never replied. kinda forgot about this thread. i had to move wires around in the plug like silverxj posted. works great now.

[SilverXJ]

Great! I'm glad we got it figured out.

[DesertDawg]

Hi Chris,

Would you happen to remember the part number of the ignition wires you used?

Best

Dave

[SilverXJ]

Summit cut to length yourself kit. SUM-G826

[DesertDawg]

Thanks Chris.

[darkcorp]

This is what you need to do:


I'm hoping that the wire order is correct because even the FSM is screwy on this. But that is what the 99 WJ adapter harness does to use the same rail as other coil rail vehicles.

Finaly I've done it!
I changed wires as decribed and everything works OK. Also installed DENSO VK16 spark-plugs as they are recommended for LPG.
Coil Airtex 5C1432, wires Tesla T139B.
Engine workes more smooth now.

[beiwulf]

Damn Chris why you gotta set the bar so high….