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MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG TD TF 1500 - Stock Distributor & Pertronix

I have a pertronix electronic ignition from Moss in my car. I've never had an issue with it. However, on damp mornings when I crank the car it runs really rough. I thought having a rebuild by Advance Distributors might be necessary.

But first I thought I would go with a change in the wires. In response to my inquiry on wires, Jeff at Advanced stated, "You can't run copper core wires with Pertronix or it'll misfire. You can't use carbon core wires with your cap. It's a catch 22."

I thought perhaps Advance Distributors might offer a wire and cap combination being they do rebuilds that would meet my needs. Upon my second email inquiry, the response I received was, "You can't use carbon core wires with your cap. Its a catch-22. There is not a cap made that you can run the correct wires to use the Pertronix without some level of signal loss. Return the Pertronix and run points. Its a flawed kit and there is no way to resolve the issue!"

Am I missing something here? I thought that my distributor could be rebuilt to handle an electronic ignition and the proper wires. I've seen other TD's with electronic ignition void of points and they ran without any negative issues.

So it's back to points. Any suggestions would be appreciated.

Thank you in advance for your help.
R C Flowers

What Jeff is talking about is a condition regarding the newer IgniterII series of Pertronix systems, those that do not use the magnet collar. The 'older' Igniters, those with the magnet collar, work fine with hard wires. A Pertronix LU-146 system should work fine with ordinary plug wires. The only issue that I know of regarding the LU-146 is the real estate battle between the rotor and the inside of the cap causing carbon dust. Bud
Bud Krueger

Bud,

I'm out of my element when it comes to electronic ignitions and the problems associated with the distributor in my TD.

I appreciate your input. Unfortunately, my approach to find remedy to a problem hit a nerve with Jeff. I think he took offense where none was intended.

I am just trying to find a solution to a problem. I saw on Advanced Distributors web site that they offered electronic distributor rebuilds and they further stated "If you don't see your vehicle listed,
don't despair! Chances are good that we DO work on them, and probably have a performance ignition curve designed to suit your particular engine!"

I thought since they were in the distributor business they would be able to point me in the right direction....no pun intended. I stated the same in my last email.

His response, "That's really insulting. You asked for plug wires to work with a Pertronix in a TD.
I can rebuild your distributor, but I can't fix an inherent design flaw with a Pertronix. I can't work miracles. If you want to spend $500 to custom build mil-spec shielded plug wires your Pertronix will work fine. That's the remedy.

Otherwise a good rebuild and points are what I recommend, or change to a distributor that can utilize resistive plug wires, in which case I'll still recommend points.

If you send me your distributor with a Pertronix in it, I won't work on it. It will NEVER run properly.
Period.
Jeff"

My questions were born of my inexperience.
R C Flowers

Bud,

I have a Pertronix Ignitor, part # LU-146LSP12.

I haven't had any issues until they other day after a lot of rain along with very high humidity in the morning.

I've been having trouble with the idle when the car warms up. I'm looking in several directions and trying to come up with an approach that first deals with adjusting the tappets, then the spark plugs, timing, etc. Before going into the carburetors.

Although I do think one of them is loading up.

Runs rich, idles fast, coughs and spits and idle drops when hot or turned off then restarted shortly thereafter.

I'm not a mechanic but I'm learning and I am enjoying the trip. I've successfully addressed a lot of issues without having to go to a professional. Thank goodness they've been simple issues, for the simple minded.
R C Flowers

Yikes!!! Must have been a bad weekend. I'll swear that I had seen that Jeff would do his thing on distributors with Pertronix Igniters. I can see a problem with an IgniterII. The IgniterII has built-in software to generate a custom ignition curve.

Granted, the IgniterII may have a sensitivity to EMF. I suspect that this can be gotten around by the use of resistored spark plug caps. NGK could sell you a set of plug wires that would work with a Pertronix in a TD.

Doesn't sound like the Jeff Schlemmer that I've dealt with. Bud
Bud Krueger

Bud,

The emails got worse, like in a bad dream.

Would you tell me please which NGK plugs I need (1/2" reach) and the part number for the plug wires?

I'll go back to the points if I have to. I just liked the idea of better reliability with the electronic ignition.

At any rate, I appreciate your time and help herewith.
R C Flowers

If you just want to try resistor plugs you can buy a set NGK BR6HS (that's the 1/2" reach). I'll get the wiring information for you in the morning. Bud
Bud Krueger

I would get some new high quality solid core wire along with resistor caps. My experience with other systems indicate that combination effectively reduces EMI.

JE Carroll

Thank you gentlemen. If I need to go back to points I'm glad to do so. I'm a real novice when it comes to distributors and electronic ignitions.

Bud, I'll pick up the plugs in the morning. Thank you for taking the time to make the recommendations.
R C Flowers

I've mentioned this on the other thread but it'e worth repeating here. The statement attributed to Jeff above is inaccurate.

"You can't run copper core wires with Pertronix or it'll misfire. You can't use carbon core wires with your cap. It's a catch 22."

I'm unable to comment on the copper wire bit, but I do disagree with the second statement.

The fact remains that the original Champion bakelite plug caps & the original Lucas distributor cap CAN be used with modern 7mm suppressed ignition cable. I know, having successfully done so myself. I used magnecores Electrosports 70 Ignition Cable SS25 Metallic Inductance EMI Suppressed Conductor All Silicone Construction. The use of suppressed cable is recommended with an Electronic Ignition such as the EI 123 & it seems the Pertronix as well.

All original Champion bakelite spark plug caps are constructed with a screw that the original copper HT lead screws into. When using the Magnacore cable it is necessary to drill out the screw & the metal spark plug sleeve, along with some of the bakelite as the wall thickness has to be reduced to ensure a snug internal fit of the new brass cable connector. Remove too much & the cap will be loose on the lead & the wall thickness will also be compromised. I purchased brass fittings from the cable supplier for both the distributor & the plug ends, both of which crimp over & into the cable & are invisible once installed.

As my crimping tool wasnt designed to secure this type of fitting, I cut the leads to the correct length, allowing a little extra for the core to be folded back under the fittings & took them to be crimped at the local auto electrician, as a special tool is required. It is essential to fit the leads into the circular fibre cable manager with the leads cut to the desired length BEFORE crimping on the brass connectors. It's impossible to retro fit it. Don't ask me how I know. By using some thinners the manufacturers branding on the Magnacore cables can be removed.

This method enables the use of an original looking ignition system including suppressed plugs, suppressed leads (overkill I know), Champion plug caps, Lucas dizzy cap & connectors, Lucas dizzy converted to the 123 EI & an original looking coil, with all the advantages of a modern suppressed electronic ignition system.

I feel it is important to set the record straight on the use of suppressed leads in our cars. There's some good stuff in the archive on this topic RC with just as many pro points owners as there are fans of the modern EI, particularly the EI 123. I want the best of both worlds with my car; for her to look original with all the benefits of "invisible" modern technology. Thats why I've gone for the Chet Herbert cam with local valve springs, 10.3 to 1 CR, a mapable dizzy with 16 curves & a 4.3 diff. But to each his own. Cheers
Peter TD 5801



P Hehir

Peter, the quote was from one of Moss' technical folks when Mort and I were asking about this issue a few months ago.

I'm curious as to what sort of fitting Magnacore puts onto the non-solid cable to allow it be secured by the OEM distributor screw caps. Bud
Bud Krueger

Peter, thank you for the additional information. I have a nephew who married a beautiful Australian woman and they live in Sydney. Her mother and father came over for a visit and we had a wonderful time.
R C Flowers

For some reason, Pertronix claims that you need resistor wires for their later, super-duper ignitions. I don't know what the reason is, but I'd take them at their word. As for the old vanilla ignitions, you can indeed use solid-core wire with them; I did this on my Porsche 912 with no problems. I also don't see why you can't use resistor wire with the stock distributor cap, as long as you have fittings that work. I've never had much luck cutting resistor high-voltage wire and making connections with it, but it's been quite a long time since I tried and maybe it's easier with modern wire. I do know of people who do it successfully.

In any case, you can use resistor plugs, and as long as there is about the same resistance as the resistor wire would have, it should work, even with the newer units.
S Maas

I'm going to have to get out of this, but it's like eating Lay's potato chips.

The original Pertronix Igniter modules uses a Hall-effect sensor that is triggered by the presence of a magnet rotating on the distributor cam. The module is a switch that effectively replaces the points, i.e., it opens and closes at the same point on the rotation of the crankshaft.

The latest Pertronix Igniter, referred to as the IgniterII, uses an electronic module that senses the location of the lobe of the distributor cam. They are called the LS series (lobe sensor), no magnetic collar. BUT, this time it is like your 'smart phone' in that it has the ability to sense the engine speed and gets involved in the ignition timing, including the advance. There's a significant difference in a simple ON/OFF switch and a quasi-intelligent module. The new module is sensitive to the electrical noise generated by the firing of a spark.

At the moment there is uncertainty as to the ability a of a set of resistor spark plugs as being sufficient to control the electrical noise. Stay tuned. Bud
Bud Krueger

Bud the quote I'm referring to here in this thread was supplied by RC & came from Jeff @ Advanced. (See the second para in the first post above.) The fitting is as I described it in the other thread, however I can't take a pic till Monday. Cheers
Peter TD 5801
P Hehir

I read the Magnecor literature. They are rather rigid about their crimper. Actually, it's the same device as that used by British Wiring, only with a different set dies.

I'm really disappointed at that quote from Jeff. Bud
Bud Krueger

As for Jeff, he took insult with my questions when none was intended. I'm used to talking directly to folks. Reading key strokes is different than voice. If I had called instead of emailed the outcome probably would have been different. In the end he doesn't get my business and he probably won't miss it. Not a big deal.

That being stated, you gentlemen are giving me good insights and I appreciate your willingness to share your knowledge gleaned of first hand experience. Priceless.

Thank you all.
R C Flowers

R.C. I attended a workshop Jeff put on at GoF Central back in July.

This question came up in the session. Jeff said that the new Petronix systems are poorly made, there is low quality control and there is the issue you brought up about the wires. From what I heard, Jeff dislikes them because of the failure rate of the new ones. As you can imagine, when a distributor he rebuilds fails, there is a bit of finger pointing.

I think he just does not like having units that put his work in question.

I have older petronix units on both my TD and my 67 B Gt. Have had them on for 10 years and not a speck of problems.

After hearing Jeff's issues with the new petronix, if one of mine failes, I would go back to points.

Jeff rebuild both my distributors with the petronix units that were in them. When I asked him about this at the session, he said that the older units are fine, it is just the new style.

Bruce Cunha

Thanks, Bruce. That sounds more like what I would expect from Jeff. I'm getting more information about the later Pertronix units. One of the issues is that standard rotors (probably Jeff's red ones included) physically interfere with the new module. The LS series comes with a Wells LU901 (or, Holden 400051 in UK) rotor. As yours, my old one keeps on ticking. Bud
Bud Krueger

As you can imagine, my enthusiasm for installing the Pertronix LS unit is waning. Jud
J K Chapin

Mine is being piqued. Anybody have an old points plate that's just gathering dust? Bud
Bud Krueger

I'd be glad to be the 3rd or 4th guinea pig but I'm too conservative and poor a mechanic to be the 1st or 2nd. Bud, please stay on it 'cause I'd really love to confidently install an LS unit. Jud
J K Chapin

The positioning of the pickup unit on the distributor plate seems to be another of the issues. Jeff mentioned that he actually has had discussions with Petronix on this issue. Seems there is no rhyme or reason to where the unit gets positioned from the factory.

You would think that they might listen to a person who has one of the best distributor rebuild businesses in the US. Just Jeff's word on these units has got to have cost them a bunch of business.
Bruce Cunha

Apart from points & the Pertronix there is the third option. I've yet to hear a bad word about the EI 123 from Holland. My original dizzy was rebuilt there about 4 months ago for less than $450 AU, inc shipping both ways. Cheers
Peter TD 5801
P Hehir

I don't want to get into a pi$$ing contest on this, but the instruction sheet for the LU-146LS says:
****
PART NUMBERS: 9LU-146LS, The condenser may be
soldered to the breaker plate on some distributors. Flex
the condenser back and forth to remove the condenser.
Position the Ignitor plate over point pivot pin and line
up hole on adapter plate to screw hole on the breaker
plate. See figure 2. Confirm that the Ignitor plate is flat
and fits without modifications. Fasten the plate into
place using the original point screw.
***
That's from them instruction sheet at:
http://www.pertronix.com/docs/instruction-sheets/9LU-146LS.pdf

I think that's pretty specific on positioning. It gets positioned where the points were. At this point I will probably buy one if I can get them to agree that it's compatible with my D2A 40368A High Lift Cam Distributor. Resolution of the EMI issue is less than the cost of a new set of Moss plug wires. Bud
Bud Krueger

I dunno. I'm like you, I don't want to get into a 'tinkle tango' either. But for the life of me, I can't see why there's such an urgent need to move away from the original points and condenser system. When properly set up it runs for bloody ages. All of my LBC's still have their original set-up and they all start with the simple twist of the key (or pull of the button)... EVERY time. And I successfully raced my Elva and my Turner with standard points and condensers for over 20 years - never had a failure or a performance issue. Is there really that much to gain by going with *any* electronic alternative? Why just not keep it stock.
Kevin McLemore

I'm installing new points, condensor and plugs. Based on the reports of the poor quality of new condensors, I'll keep the old points and condensor in the tool box. I'm still waffling on the Pertronics LS ignition but don't want to burn any bridges. Is there any reason to not use resistor plugs on the possibility that I may go with the Pertronics LS ignition in the foreseeable future? I'm currently running NGK B6HS and thing the resistor equivalent is BR6HS. Thanks. Jud
J K Chapin

I heard from from my old contact at Pertronix and I'm going to install an LU-146LS.

I do not need a new ignition system. My present Pertronix LU-146 is working fine. I can re-install my points plate and have reliable running in ten minutes, or less. But, I'm a retired EE and just can't pass up something like this that some say won't work.

I expect to begin buying the necessary hardware tomorrow.
I'll report on the results in a new thread. Bud
Bud Krueger

Thanks Bud. If I can get the TD engine back together I'd love to be the second guinea pig. I was ChemE but always envied the EEs because they could play with their gizmos in their dorm rooms whereas ChemEs needed big pipes and pumps and vats and things. Jud
J K Chapin

So if I've followed the thread I could use the LU-146LS on my positive ground and don't have to angst over whether my cam is symmetric or asymmetric and I don't have to change out wires and if I ever install a radio I won't suffer from interference???
Jon Levine

Jon, don't jump to conclusions. I am working with a negative ground system. I now nothing about the LU-146LS in a positive ground car. Pertronix tells me that the cam lobe is not an issue. EMI is a strong issue. I will be using EMI-suppression cables. Bud
Bud Krueger

This thread was discussed between 10/09/2014 and 17/09/2014

MG TD TF 1500 index

This thread is from the archive. The Live MG TD TF 1500 BBS is active now.