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Exploding Coil

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4K views 32 replies 12 participants last post by  dnp 
#1 ·
Hi everyone,

I apologize in advance if this is a dumb question or one that has been talked about before. I made every effort to search old threads first.

The ignition coild on my 94 D90 died on me. It literally opened up and leaked a liquid that looks like melted plastic all down the inner quarter panel of the truck. I went to my local parts shop to find that they didn't have one in stock and they currently have no ability to order one. If they did, it was going to cost me $138. This same place had after-market "universal" ones that looked exactly the same at a cost of $40. I was tempted to buy and install it but figured I'd check with the Source first. I am pretty handy, but do not consider myself a mechanic by any stretch of the word!

Oh, and does anyone have any idea what would cause a coil to fail like it did?

Any suggestion will be greatly appreciated.

Thanks!

Steve
 
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#2 · (Edited)
There is a service bulliten on this issue. Search "excessive dwell angle" give me a minute and I will find it. IIRC they way to fix it is with the ignition module relocation kit.

I posted this in June of 2004

"I am willing to bet the coil was the main issue. there is an interesting bulliten on excessive dwell angles and how it kills the coil. there is a whole update involved--ignition module etc. Saw it happen twice. one it actually melted the coil so it started to leak black stuff. nasty."



As far as getting the service bulliten, I would call mike at LR West Chester. He would probably send you the bulliten if you buy the ignition upgrade kit. I warn you, it is expensive as it includes a new ignition module. You could just replace the coil, but I would be willing to bet it will fail again unless you at least replace the ignition module. Roadsiderob on this board also seems to be familar with the problem based on a search for the word "dwell."
 
#3 · (Edited)
I just got this in the mail:

http://www.toddcosuspensions.com/larode90110p.html

I figured a new coil + ingnition module, with extended wires and all.. and less Lucas parts. Ill let you know how it goes.

Also, on the site somewhere there are a few posts detailing the install of a GM "ignition amplifier" equivalent, something crazy, like a $12 part!! seemed simple simple, just a few wire strips and crimps.
 
#7 ·
Gentlemen,

I too, installed a Mallory into my NAS 110 after the Lucas ignition amplifier died on the distributor and cooked the coil. The coil extruded black goo from its innards that encased the terminals. The truck ran fine but the excessive dwell from the bad amplifier cooked the coil so it was too hot to touch.

See the Land Rover Club of Diego website for the complete Mallory installation story in the Oct/Dec 2007 Newsletter. http://www.lrcsd.com/OctDec2007.pdf

HOWEVER, I am still having significant problems with the truck due to poor idle, hesitation and dropouts. Until its determined that the problem is not the ignition but something like MAF or TPS or fuel pump, I would hold off recommending the change to Mallory for someone else.

I will advise when the issue is finally resolved. This has been an issue for over a month now.
See my posting under "D-110 Died - Your Thoughts" on Feb 9th.



Dennis
 
#8 ·
#4768901 I still have my box. You have to change over the cog gear unless they have updated something. There are a bunch of us on this site successfully running the Mallory and I am certainly not discounting Dennis, but he also says he does not know what is causing his problem. I am confident that the Mallory will do no harm and more likely than not improve things although none of us know what caused your coil to have unsightly discharge ;-). What I am certainly without a doubt recommending is NOT to do that ridiculously expensive ignition module relocation kit piece of wire, but instead upgrade your distributor to the Mallory or suitable alternate. I have not had any failure of the Mallory e-spark ignition module, but if I did, I could get it for $39 from Summit next day air.

Again, not saying it is the route of the problem, but don't drop $$ on a relocation kit when for not much more you can have all that taken out of the equation.
 
#10 ·
Yeah guys im going to get a look at it this weekend. I've been having a recurring stumbling, sputtering, stalling thing on and off for a few YEARS now. My amp is still on the distrib, so that may be it, almost everything else has been gone over pretty recently...

As for the kit, It seems simple enough, just finding the right wires and doing a bit of splicing according to the diagram that was included. I'm thinking I might have to remove the distributor to get to the wires that go to my original amplifier, hopefully not, we'll see. The amp is about a 6"x6" box, so I have to make a bracket or something to mount it somewhere...

ill keep you informed..
 
#13 ·
Davis said:
#4768901 I still have my box. You have to change over the cog gear unless they have updated something. There are a bunch of us on this site successfully running the Mallory and I am certainly not discounting Dennis, but he also says he does not know what is causing his problem. I am confident that the Mallory will do no harm and more likely than not improve things although none of us know what caused your coil to have unsightly discharge ;-). What I am certainly without a doubt recommending is NOT to do that ridiculously expensive ignition module relocation kit piece of wire, but instead upgrade your distributor to the Mallory or suitable alternate. I have not had any failure of the Mallory e-spark ignition module, but if I did, I could get it for $39 from Summit next day air.

Again, not saying it is the route of the problem, but don't drop $$ on a relocation kit when for not much more you can have all that taken out of the equation.
I had the same experience. When I bought my truck, it was running like crap! I first thought it was the problem of the ignition module being on the distributor, but when I looked, it already had the relocation kit on it. After a lot of investigation, I determined my distributor was totally wiped out. Accordingly, I ordered a new OEM style distributor from one of the Rover parts houses (no benefit in telling which one). The first one malfunctioned (blew the module). Returned it, and the second one malfunctioned (blew the module) in about half the time as the first one.........After a lot of hand-wringing, I, like others on this board, decided the best thing to to was to take any semblance of British wiring out of the equation.........I replaced the distributor and coil with Mallory units, and things have been just fine ever since (background sound of knocking on wood). Just like Davis said, you can most likely save yourself a LOT of both time and money by converting to the Mallory setup (I have the same part number as his, and I installed the corresponding Mallory coil....oh yeah, some people recommend the ballast resistor and some don't - I think it's a #700 or something like that - but my experience is that you DO want to get the resistor. Without the resistor, my coil would get so hot you could just about light a piece of paper with it............) Go Mallory. Your head and wallet will be glad you did (also seems to run better than with the OEM replacement.....may be just my imagination, but it really seems like it does)
 
#14 ·
Just to add one more thing, I used Century Performance and the owner has a lot of experience with Rovers and Buick 215 set ups. I think his name is Ron, but I get names wrong all the time. 3 letter name, though. If anyone needs advice, he is who I used.

I also used the ballast resistor. I run a stock LR/Bosch coil.

David, are you running your vaccum advance? I disconnected mine since the mech. advance seemed to dial everything right in.
 
#16 ·
jimngo said:
You need an external ballast resistor with the Mallory. I initially ran it without one, thinking that the coil had an internal ballast and that would be OK, but I blew the coil, the ignition module, and damaged the cap & rotor. I wrote up reasons why you need an external ballast in this message:

http://www.defendersource.com/forum/showpost.php?p=100229&postcount=12
Yeah, the tech AT Mallory, believe it or not, told me I didn't need to install the BR, because the Mallory coil I used already had one in it....well, if it does, it doesn't work very well. It was only by accident that I detected just how hot my coil was getting (it wasn't glowing red, but I suspect it wasn't far from that). I installed the BR, and now my coil runs MUCH, MUCH cooler!
 
#17 ·
Thanks everyone! So would I be getting in over my head if I tried to do this Mallory distributor on my own? Can anyone give me a 1-to-10 difficulty rating? I'm somewhat handy and have a ton of tools. I was mostly concerned about having to drill-press a hole. Should I buy the pre-made conversion kit? Sorry if these questions are a waste of anyone's time! I usually choose to work on the Defender rather than pay someone else, but I don't want to work on it THEN pay someone to fix my mess ups!


Thanks!
 
#18 · (Edited)
For me it wasn't too difficult of a job. Probably a 4 or 5 on a scale of 10. The most difficult part was realigning the rotor when dropping the distributor back in since it rotates about 30 degrees as the gears mesh.

Drilling the hole was easy. Use the gear as a drill guide and if I recall correctly, you need to make sure you have the spacer installed when you do it.

I got my Mallory from the guys at D.A.P. and they are pretty helpful.
 
#19 · (Edited)
Getting back to this one again for myself here, as I think either my coil or module has dropped its pants and mooned me. I'm going to give the HEI module swap a try, but want to replace the coil at the same time.

I just want to make sure I get this right..... going with an aftermarket coil, I need to add the ballast resistor? I've got a '94 with the original module on the distributor still.

and a dumb question, as when my problem popped up I found that that little silver can right next to the coil was disconnected. What is that thing anyways? reconnecting didn't solve the problem, but I wonder if it may have been a cause.

-Hans
 
#20 · (Edited)
Hans, since nobody replied I'll throw in my 2 cents. You need a ballast resistor--external or internal, it doesn't matter--with the stock setup or with the ignition module relocation kit. With a Mallory you definitely need an external ballast resistor, not an internal one.

The silver can: I'm guessing it's a low-pass filter capacitor.
 
#21 ·
Gentlemen,

I got nowhere with the Mallory replacement system in my 93 D-110. It replaced the Lucas ignition after the ampflier failed and cooked the coil.

After a couple of months of troubleshooting to try to fix the constant stumbling upon light acceleration, I gave up. I pulled it out and put the repaired Lucas back in. Truck runs fine with no hint of the hesitation problem.

My point of view from this episode is that the Mallory is NOT compatible with D-110 for an unknown reason. Honestly dont know why, but it doesnt work right.
 
#22 ·
Hello hello....
Well it's been 2 years since I posted this original thread. Since then I had the Defender in a barn collecting dust. I'm back at it with several projects. Any updates regarding thoughts from this thread? Is there a better product I should be considering. So far I am leaning towards a Mallory distributor.

Thanks in advance everyone.

-Steve
 
#25 ·
Wow, I definitely learned a bit since my last post on this one :)

I went with the full mallory install eventually, and initially had the same problem with stumbling, etc....
Eventually I fried the module (welding on the exhaust, forgot to disconnect it, totally my fault) and replaced it with their newer E-Spark module. The E-spark had an addendum sheet with an alternate wiring schematic, to feed 12v to the module instead of the 6v in the older diagram. Huge difference, no more stumbling and has been running fantastic ever since.

I went full mallory on the ignition with the unilite/e-spark distributor, e-spark coil with external ballast resistor, mallory wires, etc.....

You really need to upgrade the plug wires I found, the stock style generic brand wires kept burning up between the wire and the plug connector. No problems since going with a beefier plug wire.

-Hans
 
#26 ·
In early June I was doing the hole in the rock trail in southern Utah and on day two deep in the desert in the middle of nowhere my coil melted down. Luckly there after a day some jeeps came by and one of the guys had two spare coils. I cut some wires and made it fit (I had no choice). It worked fine for about 20 minutes when that coil melted down also. By that time the jeep people were gone. But two days later they found me again but this time I had to buy the coil. Hooked it up and with a volt meter checked the volts coming from the alternator and it was around 18 at that point I disconnected the alternator and ran on battery power luckly I had a friend with a dual battery setup and we could swap. I drove home about 10 hours. Replaced the alternator and the coil and the problem seems to be fixed. So check the volts coming from the alternator before changing the distributer and such, mine still has the old style w/o the relocation kit and has been working fine.
good luck and sorry for the long story.
 
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