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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 - Pertonics ignition: Love/Hate

IMHO: My biggest mistake installing the Pertronics? Not purchasing a spare one 12+ years ago?

Over the years I have seen much about these units pop up on this BBS. Disturbing to me is that a large number of people here who’s opinion I sincerely value as experts tend to not like these units.

Mine has been in service for over 12 years without a problem. My experience has been easy / fast starting, smooth acceleration, and great running through all RPM’s.

I really have to wonder if at some point, when popularity grew, if these got “outsourced” to meet demand and quality went way down. (This seems to be a trend in many areas of manufacturing.)

Kind of wish I had bought a “spare” when I got the first one! I carry a spare set of points in the car, (as well as spare cap, rotor, condenser, and plug wires.)

Just curious: Did any of our experts, (those on this board that work on these cars for a living) notice a trend here?
i.e. Early units worked better than the ones now being sold?
David Sheward

David, mine has been in the car for over 7 years and no problems. I too carry a spare set of points just in case but I love the pertronix. Car starts right now and no problems.
Tom Maine

I had 2 mgbs for 10 years in the nineties. One had a pertronics the other points. Over the 10 year period
I had about 5 hard failures of the pertronics, one caused by my checking the compression with all plugs removed and the ignition system powered up. The one with points had one failure when the little wire in the distributor broke.
In addition to the Hard failures I had an intermittent
problem which I never did find. Kinda like the 777 crash/disappearance. Every time it left me stranded on the side of the road I would take it apart and wiggle the wires and it would start working again. I sold that car to a neighbor with a caveot, don't call me if it stops. He has not called!
I have a pertronics in a corvair right now that has yet to fail over a 12 year period. It runs good and starts all the time, but so do my cars with points.
I vote "NO"
chuck
cj schmit

David, the Pertronix unit that I have in Lazarus was purchased from the late Skip Kelsey in December, 1998. It has never failed me. But it was responsible for the carbon contact failure (http://www.ttalk.info/Failure.htm). I have seen units that failed due to owner's wiring issues. Biggest hazard is the positive-grounder who green-thumbs the installation. But, I have yet to see one that failed after having been in operation.
I have concerns about the effects of the rubbing against the carbon button. I detected that last week when I removed my distributor cap and wires. The rotor had been shaved down about 2,000 miles ago. Bud
Bud Krueger

I've used them, as well. I think they work fine, though they wear out and eventually fail like anything else. They require a lot less maintenance than points and more accurate firing if that's something that you value. Probably cheaper than replacing a worn distributor.

Some people have immediate trouble with them because they don't have the right ballast in their ignition system. Though I think Pertronix did a redesign that avoided them being burned out quickly because of this.

Another failure mode is that the ring with the magnets inside the distributor will open and drop a magnet. You'll know this has happened because you'll get firing on all cylinders except one.

I wouldn't hesitate to use them on my street MG's. I used one for a number of years in my racing midget and it worked well, except for the magnet drop issue.

I replaced the one in the racecar with a 123 distributor eventually. The 123 is very robust, has programmable curves, and it uses a Volvo Bosch distributor cap and rotor, which are unbelievably sturdy compared to the chintzy stock Lucas and aftermarket caps and rotors available for British stuff.

Doesn't look stock, though, so not for the purist:

http://www.123ignitionusa.com/
David Littlefield

I know several people locally who run them without issue, and also several who have suffered complete and sudden failures. It seems to be luck of the draw.

Cost is about the same to rebuild a points dizzy, or to buy a Pertronix. Keep in mind though, that while the Pertronix will remedy the running issues associated with a worn dizzy, it does not fix the root of the problem - sloppy dizzy bushings. You should really address the root of the issue first, and then install the EI unit if you so desire. Just my opinion.

The only design change I know of (and I'm hardly a Pertronix expert) is that the early ones would burn up if you left the ignition on without the car running. They have since added protection for that. They are still (correct me if I'm wrong) polarity sensitive so don't let anyone connect your battery with the wrong ground or the unit will fry. That's how the ignition in my only EI-equipped car (my MGC) went bad. The car was down while I ordered another unit so I could get it out of the body shop on its own wheels.
Steve S

I've used one on mine for 2000 miles without any problems. I replaced the old rotor button with the red button that appeared to me to be of higher quality. I had to use a small belt sander to buff the red rotor so it would fit properly.

R C Flowers

Steve's point is interesting "worn dizzy".
Something I had not considered.
My dizzy was re-built (same time as engine)...the Pertronix was installed after the re-build.
Has me wondering now how many of the "problems" with these could be associated with a worn dizzy.
David Sheward

The only problem I ever had with mine was after I left the car sitting for several years and whatever glue/sealant they'd used in the piece that goes around the cam on the distributor failed, allowing all the magnets to fall out. Finally figured out which way each magnet went, glued it all back together and it's worked fine ever since.
Gene Gillam

I had one fail in my B because the wire between the rubber grommet and the unit fatigued right at the unit and started having an intermittent open circuit. Took a while to figure that one out! But I simply replaced it (rerouting the wire slightly) and carried on.

Haven't yet put one in the TD but I intend to....
Rob Edwards

Got mine from Skip about the same time as bud. Love it. Not a problem one- Well, Dave Braun did find a bare wire from where it was rubbing.

Put one in the B back in 2006. Works perfectly.


Saying all that, I do have a set of points all mounted that I carry in each car as a "just in case"
Bruce Cunha

When y'all refer to carrying a set of points on a plate are you referring to item 4 on the electrical page of Moss (152-900 and all the stuff - condenser and points - attached to it? Can you put the plate in, set the points, take the plate out, put it in your tool box and then put it back in without having to re-set the point gap at least to limp home?

Thanks.

Jud
J K Chapin

Jud - yes, that is what the bare points plate is. But the complete set-up is 163-700.

You can get a guestimate of the points gap by doing what you say, but there is no precision in the way it fits back in, so the setting is probably going to be off (a 93% chance). The old technique (not PC now), is to set the points with a matchbook cover, which is close enough to get you going.

Tom Lange
MGT Repair
t lange

Should probably note on this thread that if you remove the pertronix and put points in on the side of the road you will have to re-set timing ...make sure you carry a wrench to do so!
David Sheward

Having grown up cleaning & gapping points (sometimes along the side of the road with a matchbook, right TOM?) I kinda like our Pertronix. I matched it up with a cheapo chrome coil and good old fashioned ballast resistor and have a great spark.

My wife used to complain about every other year, her limey toy would be running a bit crappy and I'd have to do some points filing, gapping and then doublecheck timing.

A long time ago, I looked at an MG for sale with a Pertronix that wouldn't run because it had been "detailed" and the igniton was wet. Go figure, a Hall Effect device that crapped out when wet. It fired up the next day after drying out. I seem to remember ours got wet once and didn't cooperate for a spell.

JRN JIM

I have ca 9.000 miles on my TF with Pertronix. Never an issue, and the car instantly became a better performer. Starting was easy with points as well. My brother and I have done something like 25.000 miles on our old Indians with a similar Hall effect electronic device as the Pertronix. Never had problems.

My best advice would be to carry a spare hall sensor on longer trips.

The latest Pertronix is cam lobe triggered, and the revolving plastic ring with magnets is a thing of the past; the sensor reads the bare distributor cam, which I find a very neat solution.

regards,

Jan
Jan Emil Kristoffersen

When I installed my Pertronix I took the points plate out and put it into a small plastic box in Lazarus' tool box. A number of years ago I gave annual demonstrations on installing a Pertronix unit and reinstalling the points plate. Never had to reset the points.

Jan, that model of Pertronix is not available for D2A distributors. I sure wish that were. I'm growing leery of the effect of the ring upon the rotor position. Jan, is that type of Pertronix available in Norway? Bud
Bud Krueger

Sonuvagun, it looks as if the 'LS' (lobe sensor) version may be available after all. It's their 9LU-146LS. This is in their IgnitorII line. A problem is that it's listed as for the DKYH4A distributor. There is an LS version for the DKY4A distributor in the Ignitor line, but I can' t find information about it. The IgnitorII instructions specify 'DO NOT USE WITH SOLID CORE SPARK PLUG WIRES." Looks like it's time to call Pertronix. Bud
Bud Krueger

Wow! I had planned on getting and installing a Petronix shortly after I got the TD then, after reading all the posts, I decided to stay with conventional points and condenser but now I'm leaning back toward the Petronix, especially if they have a cam-lobe sensor version for my dizzy. I'm becomming a real waffle.

Are the dizzies labeled or stamped with the type?

Thanks.

Jud
J K Chapin

David, I don't think a worn dizzy will noticeably affect Pertronix unless the problem is severe. Most people seem to install the Pertronix because the points aren't working well, unaware that the reason for the running issues is the worn out dizzy. The car runs better, so they assume the Pertronix is simply superior to points.

I think the only real advantage to Pertronix is that they run the same all the time, where points will run perfectly after each adjustment and then very slowly degrade until the next one. But when either one fails, the points have the advantage because they virtually never fail completely like a Pertronix will.

I wonder if it has something to do with climate, but I adjust the points in my cars that are equipped with them about once every 10,000 miles. Never have to file them down on the side of the road, either. My new XPAG now has several thousand miles on it and the points are right where I first set them. Or maybe I'm lucky.
Steve S

Bud; My TF1500 has the original dizzy. The LU 146LS kit is what I received from Moss whem I ordered e negative ground Pertronix kit. I also bought a Pertronix Flamethrower coil that is supposed to be suitable for the Petronix kit. Lobe sensor triggered, very elegant, and works like a charm - so far.

I will never go back to points. Period. But then I am all for discrete improvements of the breed. Five speed T9 box, Racemettled alternator, electric rad fan, halogen front lights and Koni rear dampers are a few of my sunk costs into this car so far. My wife understands - she can see that it keeps me happy

regards Jan


Jan Emil Kristoffersen

I had points fail completely- the rubbing block broke off and killed the car. Pertronix perfect for many years, vastly smoother and better running all the way around. George
George Butz

I have had my Pertronix for over 5 years and I would never consider installing the points again. My TD starts immediately and runs well at any engine speed.
I am still using the original Lucas coil.
Jim Merz

Thanks, Jan. It looks as if the LU-146LS is, indeed, the lobe-sensing version of the LU-146 that I've been using for about 15 years. I've become concerned with the rotor/carbon brush issue. Bud
Bud Krueger

TF3719

Uses all the original Lucas gear(albeit some NOS,from the fifties) nothing has ever failed in anyway since restoration ten years ago over the cars entire electrics.Love the 'real' Lucas!

With regard to points,the 'modern' green packeted so called 'Lucas' product,are not made of the same quality
of the red fibre heeled originals.They are plastic junk.

Had a Triumph Stag for nine years.A magnificent car to drive after the previous owner had restored the original motor with the upgraded water pump,fan,etc.However,the only thing changed in the electrics department was to
a Pertronix unit.That failed after three years!

Cheers
Rob Grantham
TF3719(Aramis"),TF9177("Athos").
R GRANTHAM

I think it's fair to say that any product, points or Pertronix, can suffer a manufacturing defect and fall to pieces. The only fair way to compare is with a properly functioning example of each.
Steve S

The producers of the Pertronix units have info on their web page telling you that they have been making electronic ignition units for decades, so far having produced 3,5 million units. So definitely not a cottage product.

http://www.pertronix.com/about/default.aspx

But still, this discussion reminds me I should bring a spare kit on longer journeys.

regsrds

Jan
Jan Emil Kristoffersen

This thread was discussed between 25/03/2014 and 27/03/2014

MG TD TF 1500 index

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