Hi, I am having problems with my ignition wires and have heard many differing opinions around what type of wire should be used. I noticed that the OEM wires in my 97 F355 Spider had blue auras around them and flashed at night, so I decided to change them. I looked around and found what appears to be OEM wires for about $2000 and aftermarket wires for around $400-$500. I purchased the aftermarket wires and installed them. The car seemed to run fine for a few days, then started missing out eventually sounding like a low flying helicopter. I took the covers off and noticed that the wires were very deformed where they went through the small rubber gasket into the covers and the insulation on one of the wires had melted away exposing the copper wire inside. I contacted another source for bulk ignition wire and purchased new 7mm copper core wire which I used to replace the wires for all 8 of the ignition cables (re-using the boots). This again worked for a few days then I started hearing significant EMI in the radio. After a couple weeks it was missing out again. When I pulled the covers off, the wires were again permanently distorted at the rubber gasket as well at all of the compression points where the cables were routed around the plug boots. A few people commented that I should be using wound wire instead of copper core wire, so I contacted my bulk wire provider and ordered 7mm mag-wound wire and rebuilt the full set of cables again. Again I had similar results. After a few days, the EMI returned, then it started missing out. This time I left the rubber grommet out, but the wires are still permanently distorted at all of the pressure points. I contacted the bulk wire provider today explaining my issues and they said that I should be using copper core wire only with boots that have built-in resistance as in my application. I have heard differing opinions on this so I am looking for some more feedback. I have a full set of plug and coil boots and I am trying to decide what type of wire I should use to avoid the degradation that I have been seeing. Opinions? On a side note, I have destroyed 4 plug boots trying to remove them. I have gone through 3 different tools types with varying issues. The latest tool splits the rubber cover and pulls it off the boot without extracting the boot. Any recommendations? Thanks for any help. Tom
There are resistors (approx. 5K ohms) in the connectors. Kingsborne sells a decent set of aftermarket wires. They're a cost-effective choice. I suspect your problem is really somewhere else. Spark plug wires don't typically deform and melt unless things are a lot hotter than normal.
My coolant temperature hovers around 195, so the engine doesn't seem to be overheating. I checked the coils and they measure about 13.7K Ohms on the secondary and about 0.5 Ohms on the primary, so they seem alright. Any thoughts on wound vs. copper core? BTW, Kingsborne is what I used for the replacement wire in both cases when I rebuilt the cables. - Tom
Either the routing of the cables under the cover is wrong or the wires being used are the larger wire. Or both. No reason for them to get squished and damaged otherwise. Kingsborne sells them in the large and small wires. I have no idea why, the large cannot work. Americans separate and insulate the wires from each other and the Europeans have always smashed them together in a metal enclosure. It was never a good idea and always left me wondering if the really understand electricity?
I purchased the 7mm wires from Kingsborne in both cases. I wasn't aware that there is a proper routing for the cables. Is there a diagram or photo somewhere that I can refer to? LOL. I was wondering the same thing. I think the wires start to arc at the points where they are compressed. I moved them around a little and they worked fine for another few hours, then started missing out again. I have talked with a few CAD people about designing a 1/4 inch spacer to create some more room for the wires and maybe bring them out on the top side of the spacer instead of the left/right side. - Tom
I just replaced my plugs and wires. Wires came from Ricambi. They are the same size as the OE wires. They needed a little boot (dielectric) on the boots to get them to seat properly. Without lube I don't think I would have been able to get them on without destroying them. If you had trouble getting the metal covers on, then the boots weren't seated all the way and that could have been causing a problem. With some effort they can be routed to give minimal pressure on them.
The boots are seating fine. My issue is at the point where the wires exit the cover. Also, there is some deformation in the areas where the wires route around the boots under the cover. Here is a photo of the damage at the exit point. These are my original Ricambi wires which I replaced with Kingsborne wires and had the same results. Image Unavailable, Please Login Image Unavailable, Please Login
Wow. That is bad. Maybe i need to recheck mine. Mine didn't seem that tight. These wires are too expensive to keep replacing.
Please do. I'm curious if someone else sees the same issues. This was after about 8 hours of total driving time over a two week period. - Tom
Weren't there sets of 8mm wires out there for awhile? They were very tight in the valve cover tray. I bought a set of Kingsborne and they only make them in 7mm now. Are you sure the wires in the pic are 7mm and not 8mm?
Will do. FWIW, there is a small 4 hole rubber grommet that goes around the cables as they exit the valve cover to seal them. One of mine was missing....replacement is a mere $75! Is it possible yours is squished under the cables? Looks like it might be in the picture, but it isn't clear. I would think if you can't get that grommet to fit with the wires, then you may have 8mm wires. #49 in the diagram. Image Unavailable, Please Login
I have the 7mm Kingsborne wires and they fit excellent with no pinching or fitment issues at all. They fit throught the rubber grommet in the head perfectly. I also just installed the Gothspeed ignition wire reroute kit which moves the wires away from the headers; I highly recommend this upgrade!! The last pic shows the difference in wire routing: stock on right, Gothspeed on left. I guess my only data point is that my 7mm wires fit very well with no pinching. Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login
Also, make sure you have the wires exiting the head in the proper order. It is specific which wire goes in which spot otherwise they don't all lay flat under the cover and will get pinched.
The new Kingsborne mag wound wire looks to be about the same size as the original Beru wires. The previous photos were of the Ricambi wires, but they also appear to be about the same diameter. In fact, the plug boots appear identical to the Kingsborne boots so maybe they are sourced from the same place. Also, the Kingsborne and Ricambi wires are made with a softer rubber than the Beru wires. I'm not sure if it's just because the Berus are so old though. - Tom Image Unavailable, Please Login Image Unavailable, Please Login
Yes, I also have the Gothspeed reroute kit installed. It was part of my project to replace the ignition cables. They look great with the red cables. Maybe I need to get some red wire and rebuild my cables again. - Tom
I got a set from Kingsbourne as well. They were made in Italy branded CAI http://i1374.photobucket.com/albums/ag421/badabingjr/29CDCDDF-6A8D-4AEE-8E5D-32131DF5D401_zpsewkqx8y1.jpg http://i1374.photobucket.com/albums/ag421/badabingjr/F8A98ABF-4858-41DB-ABDB-9B1766377DF5_zpspd6d7dce.jpg http://i1374.photobucket.com/albums/ag421/badabingjr/9B5AD22F-AE4F-4C9C-917E-0040E0C0C945_zpslrmgsi7k.jpg Marked 7mm. Good fit. Gothspeed Reroute. So far so good.
Yes, these are the more expensive ones that are now available via Kingsborne and are allegedly OEM wires from Italy (according to the rep that I talked with yesterday.) I only ordered the wire from Kingsborne to replace the wire in the cables that I obtained from Ricambi, so I do not have these cables. My fallback might be to just order a complete new set of the Italian cables, but I'd like to try to get the ones that I have to work first if possible. BTW, Ricambi has been working with me as well to try to help resolve my issues, so I have no issues with them. They have been more than helpful, even sending me replacement parts to help rebuild my cables. My goal is to finally resolve this so that anyone that runs into a similar issue in the future can look through this thread and hopefully resolve it quickly. - Tom
