Renix Ignition Info

I am preparing to do a tune up on my 1989 Comanche 4.0 and would like to mildly upgrade the ignition system quality if possible. Plugs, rotor, cap, suppressor wires, and coil. This pretty much a daily driver (96,000 miles) that I plan on keeping as long as I can.

Thanks............

i not sure if they have one for renix but my firepower ignition kit came with cap, rotor, wires and coil. got it from quadratec.

You can throw alot of money at "performance" ignition parts and get about the same result if you just give it a solid tune up with regular parts. New wires, plugs (don't waste your money on super-duper plugs, the RENIX likes stock or close to stock plugs), cap & rotor, coil and coil module.

They'll last just as long and cost you 1/2.

Just my .02

The ignition system plainly doesnt need to be improved. Its usually good to 300HP as long as you have a good set of wires.

This is what i have done (and recommend to you):

Leave Stock ignition coil.

Get a good distributer cap and rotor. Make sure they have BRASS terminals. Borg Warner, and Accel are usually excellent canidates.

Go with Champion Truck Plugs for your spark plugs.

Get a good set of plug wires. Borg Warner (Im talking about the NASCAR set) is decent if you are getting it at your local store. I personally swear by Magnecor wires now, but they have a hefty price tag:

www.magnecor.com

I got the KV85's (8.5mm) Part # 6544 for the RENIX, Part # 6595 for the HO 91-98. When i first bought them i got the 6595 set because i had planned on swapping to a HO 7120 head onto my RENIX block, but the coil wire was not long enough so i had to send them 10 more bucks for another coil wire that was longer. Even when i build my stroker and use a HO head, the wire set will still be for a RENIX unless i changed the location of the COIL like in latter years (which would be silly).

nope the firepower ignition isn't available for the renix motors.

I've had the best results with the stock setup, the ignition seems to be one thing they designed well. If it ain't broke don't fix it.
I have gotten rid of a nagging idle miss on two Renix's now with helical or solid core plug wires. The catch is to leave the stock resistor wire between the coil and the cap. The coil to cap wire resistance seems to be fairly critical for a good idle.
I also replace my cap and rotor often, they seem to wear quicker than the plugs and other components.
One spot rarely cleaned or even looked at, is the coil to module connectors. I had a weak spark and that turned out to be the problem.

Did you have any radio interference when you changed to the helical or solid core plug wires?

8Mud said:

I've had the best results with the stock setup, the ignition seems to be one thing they designed well. If it ain't broke don't fix it.
I have gotten rid of a nagging idle miss on two Renix's now with helical or solid core plug wires. The catch is to leave the stock resistor wire between the coil and the cap. The coil to cap wire resistance seems to be fairly critical for a good idle.
I also replace my cap and rotor often, they seem to wear quicker than the plugs and other components.
One spot rarely cleaned or even looked at, is the coil to module connectors. I had a weak spark and that turned out to be the problem.

Click to expand...

Ecomike said:

Did you have any radio interference when you changed to the helical or solid core plug wires?

Click to expand...

I had a slight tick for awhile, but it disappeared. Seemed to be only form the passengers side speaker. The other front and the rears never did cause any problems.
My CB never picked up any static either, but I have pretty good filters on the CB.

Autolite....I've heard from mechanics that Autolite plugs (OEM?) work the best in XJ's with 4.0 Renix. Echo the thought that it's not worth the moneh for fancy plugs in the Renix 4.0.

Ecomike said:

Did you have any radio interference when you changed to the helical or solid core plug wires?

Click to expand...

This may appear to be a thread hijack but bear with me.

Funny you should mention this. I've always had marginal radio reception. I can get crappy reception from local channels, yet great reception from Boise (I live in N. Calif).
I've always thought that the nimrods at Best Buy just failed to hook up a decent antenna connection.

I have 8mm suppressor MSD wires (I've thought since I got them that I pounded that cash down a rat hole) but I still have reception issues at idle and at freeway speeds (65-70)

So, with my Spring Makeover I intend to just go with OEM style wires. I have 220K+ on the clock and my plugs are a healthy tan. I just passed smog with flying colors. My O2 sensor is spot on according to the DMM. The last time I changed my cap/rotor they were scored and somewhat corroded/electrolized. So like said before I'll be doing that too. I have yet to change out my ICM and coil. I bought an MSD coil off ebay that said it would fit any XJ from 87-02 (they were wrong, I got my $$ back)

Like 8Mud says the one thing that RENIX did well is the ignition setup because I've had minimal issues over the last 100K miles since I got the Jeep. In closing, does someone have a PN for the Champion "Truck" Plugs because when I go into AZ or Kragen they'll just give me the Bosch or Autolite plug.

I've been using Autolite Platinum for years (AP3924, IIRC) without any trouble. I quit using Champions in anything larger than a lawnmower years ago, after having a set explode in my Bug on I-65...

I'm not likely to get any fancier than AP. I tried the Bosch Pt plugs when they came out, but I didn't like the shrouded tip and they fouled rather quickly. The Autolites have an "open tip," and stay nice and clean - I think I've been using them for 16-17 years in just about everything now...

Muad'Dib said:

The ignition system plainly doesnt need to be improved. Its usually good to 300HP as long as you have a good set of wires.

This is what i have done (and recommend to you):

Leave Stock ignition coil.

Get a good distributer cap and rotor. Make sure they have BRASS terminals. Borg Warner, and Accel are usually excellent canidates.

Go with Champion Truck Plugs for your spark plugs.

Get a good set of plug wires. Borg Warner (Im talking about the NASCAR set) is decent if you are getting it at your local store. I personally swear by Magnecor wires now, but they have a hefty price tag:

www.magnecor.com

I got the KV85's (8.5mm) Part # 6544 for the RENIX, Part # 6595 for the HO 91-98. When i first bought them i got the 6595 set because i had planned on swapping to a HO 7120 head onto my RENIX block, but the coil wire was not long enough so i had to send them 10 more bucks for another coil wire that was longer. Even when i build my stroker and use a HO head, the wire set will still be for a RENIX unless i changed the location of the COIL like in latter years (which would be silly).

Click to expand...

X2 Renix motors (and HO's for that matter) all came with excellent ignitions from the factory. :sunshine:

I having been using a single tip, Autolight Platinum for 4 years, 25,000 miles on my Renix and they still look brand new! I think it is the same part number you posted!

5-90 said:

I've been using Autolite Platinum for years (AP3924, IIRC) without any trouble. I quit using Champions in anything larger than a lawnmower years ago, after having a set explode in my Bug on I-65...

I'm not likely to get any fancier than AP. I tried the Bosch Pt plugs when they came out, but I didn't like the shrouded tip and they fouled rather quickly. The Autolites have an "open tip," and stay nice and clean - I think I've been using them for 16-17 years in just about everything now...

Click to expand...

On the radio noise, try running a direct ground wire from the radio and antenna to the battery negative post! My radio noise disapears when I turn off the engine and the AC Blower. It got better with new larger ground wires!