Suspected Pertronix failure

[RDKeysor]

Having cured my recent carburetion/timing issues, I enjoyed a brisk 20-mile drive in my '60 BN7 yesterday until. . . .it quit at a stop sign in my community. Towed home. This is a negative ground car with a Pertronix ignition installed by the PO. (I put one in my Jag Mark 2, and I'm not a candidate to return to points.) So, the fuel pump is operating, the car turns over briskly, and there is spark at the coil and no spark at the plugs. I attached my timing light to the No. 1 wire and got no flash while turning the engine over with the starter. Also tried putting the connector on the coil wire, which I know had power with the same negative response. I don't know whether one would expect the timing light to flash under these circumstances. I suspect the Pertronix has failed. Anyone familiar with the Petronix failure mode and the best way to diagnose failure (multimeter, etc.) before I invest in a new unit?

 

[steveg]

Having cured my recent carburetion/timing issues, I enjoyed a brisk 20-mile drive in my '60 BN7 yesterday until. . . .it quit at a stop sign in my community. Towed home. This is a negative ground car with a Pertronix ignition installed by the PO. (I put one in my Jag Mark 2, and I'm not a candidate to return to points.) So, the fuel pump is operating, the car turns over briskly, and there is spark at the coil and no spark at the plugs. I attached my timing light to the No. 1 wire and got no flash while turning the engine over with the starter. Also tried putting the connector on the coil wire, which I know had power with the same negative response. I don't know whether one would expect the timing light to flash under these circumstances. I suspect the Pertronix has failed. Anyone familiar with the Petronix failure mode and the best way to diagnose failure (multimeter, etc.) before I invest in a new unit?

Often if it has failed, the label on the module will be blistered due to excess heat from shorting out. I had one fail due to an internal short in the coil, which at the time was a cheapo auto-parts-store brand. Pertronix tech support verified this happens.

There have been QC issues with the Lucas Sport coils; suggest either a Pertronix coil or the Bosch Blue coil Advanced Distributors sells. I like the latter as it's resin-filled and not subject to failure due to mounting position. Whatever coil you use should be the un-ballasted type.

Troubleshooting can fry Pertronix, too. There is a document of troubleshooting dos and donts on Pertronix' website.

 

[Keoke]

Weii:

To convince yourself at little effort, just pull a spark plug ground it connected to its wire on the engine block.
Now turn the engine over and see if the plug fires.
No fire dead Pertronics

Yeah could be the rotor like John & Michael said.

 

[Jerry]

this may help. Just did it on a MGB /

See attached pic.
1. Connect the ignitor plate to the battery negative terminal
2. Connect the red ignitor wire to the battery positive terminal
3. Attach the black lead from the voltmeter to the ignitor black wire
4. Attach the red lead from the voltmeter to the ignitor red wire
5. Rotate the magnet sleeve in front of the module; the meter shoudl fluctuate between battery voltage and 0 volts
6. A constant measurement indicates that the power transisitor or hall cell may have failed.


Bob at BritTek helped me diagnose my problem. He said:
"
Your car has the Lucas "Constant Energy" system. It uses a very specialized coil to run with this electronic system. So changing out the coil without putting the Pertronix kit in the dizzy isn't a good idea. They are matched to each other, but neither will work well with the stock components. Also that Pertronix kit will only work with the CE dizzy and doesn't fit any of the other Lucas units. The original CE dizzies are no longer available.
"

The folks at Pertronix were also helpful. I called their Tech Support line and talked to Marvin. He sent me the test above and some other tests too.

---

Tim W.
80 MGB LE "ZOM B"
73 MGB GT "Royale with Cheese"
71 Triumph TR6 "TRawler"
"Modern cars - they all look like electric shavers." - Marv (Sin City)



Edited 1 time(s). Last edit at 2006-09-30 07:00 AM by NovasTaylor.

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Attachments:

pertronixIgnitorTest.GIF 15.6 KB open | download


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[John Turney]

If there is spark at the coil and no spark at the plugs, check your rotor and cap. That's where I would start. Bad rotors are common, especially if there is a rivet holding the arm.

 

[Michael Oritt]

I'd suspect the rotor as the more likely candidate before a pertronix and in any case it is easy to test simply by putting in a new one. If no spark then I would test the Pertronix as suggested or even better simply replace the module with your spare one. (What--you don't carry a spare module????)

The cap might also be cracked and though the failure resulting from that is more often a misfire it could be total. Test with (wait--here it comes...) your spare cap.

 

[DerekJ]

'Your car has the Lucas "Constant Energy" system. It uses a very specialized coil to run with this electronic system. So changing out the coil without putting the Pertronix kit in the dizzy isn't a good idea. They are matched to each other, but neither will work well with the stock components. Also that Pertronix kit will only work with the CE dizzy and doesn't fit any of the other Lucas units. The original CE dizzies are no longer available.
" '

I'm not sure I fully understand this. All a Pertronix needs is a coil between 1.5 and 3.4 ohms, it slots into the exiting distributor without any problem. The Lucas constant energy system was a Lucas Electronic ignition system which of course has nothing to do with Healeys. Is he suggesting that your car has been fitted with some kind of special distributor, as this would not have been necessary to fit a Pertronix. Buying a special coil isn't required either.

I assume you've checked the obvious, the wring from the coil to the distributor and earth.

Generally its not obvious if one has failed, the only way to be certain is to return it where they can test it on special equipment. I always carry a spare, just in case, which is easier than having to switch points back in.

 

[RDKeysor]

Thanks, all. I am currently assessing all of this sage advice. I think Michael may have it covered best: I need to have a spare module, spare dizzy cap, spare rotor. Etc. Or maybe extra car. So I going to make some of the checks suggested above, most particularly grounding a plug to check for spark (again). I'll also check the wires and associated components. If I don't find the culprit, I may as well go ahead and buy another Pertronix module to have as a spare, along with Michael's check list. If it turns out that the newly purchased Pertronix doesn't solve the problem and none of the other ignition parts do either, I'm going to reread Jerry's suggested check system. I'm sure it will work, but as I prepare to observe (not celebrate) my 78th birthday, I found that pretty intimidating. The real solution to these Healey issues is a duplicate car. Two of our guys from the Jacksonville Healey club were recently at the wonderful Brit car show in Safety Harbor near Tampa, both with 100-4s. I started to say both driving 100-4s, but you will soon find that wouldn't have been accurate. It's a pretty long haul down there, but our guys are made of stern stuff. On the way back up here to Jacksonville, one of the 100-4s perished alongside the road. Some wit said it may have been the victim of one of our club tech sessions. But not so! In any case, the other 100-4 owner in this two-car caravan, the provident one, unloaded his beautiful car from his trailer, the tormented one was loaded into the trailer, and the two 100-4 owners drove on up to Jacksonville in the former trailer queen. The one that will soon have its gear box replaced, I might add. Let's assume one of the spouses drove the tow vehicle with the perished Healey. Oh yes, the problem was a failed freeze plug. And of course the subsequent tech session discussion included a bit on nomenclature, is it a "freeze" plug or a core plug. Core won the day. To add a bit of useful information to this diversion, I'll add that the replacement core plug, and this was a rather elegant and practical bit of engineering, came from O'Reilly Auto parts. As a measure of how the guys in our club man up (we are talking fellowship here), the owner of the now-repaired 100-4 passed out a few spares to other club members. Add one to your spares check list. To sum up, it's a chilly morning here in the Jacksonville area--chilly is a relative term as I was raised near Lake Erie--and I have taken you on this wandering epic to avoid going out in the garage and getting at it (again). But I'll be back

 

[steveg]

Generally its not obvious if one has failed, the only way to be certain is to return it where they can test it on special equipment. I always carry a spare, just in case, which is easier than having to switch points back in.

If the cause of failure is external, such as a coil short, you may destroy your $100.00 replacement as well.

IMO it is better to have a spare distributor or spare breaker plate with points along with a wiring diagram. I made index marks between my distributor base plate and the block, so it would be easy to remove the distributor and install the points setup without dropping one of the little screws into the distributor body.

 

[RAC68]

Hi All,

Although I have installed a Pertronix electronic ignition on my TR7 with no issues, I had originally installed an Allason/Crane-Cams XR-700 Optically triggered ignition more than 20 years ago with NO issues and continued great performance. I do understand that many who have installed the Pertronix unit like the fact that it all fits under the distributor cap with little indication of a change from original and the Crane requires the mounting of a box outside of the distributor. However, the number of Pertronix ignition failures being experienced by Healey owners may make the Crane ignition's higher cost (approx. $10) and external box (easily hidden) something that should be reconsidered as a replacement for the failed Pertronix.

Also, as Steve suggested, having a spare points setup (with diagram) to return to original ...just in case... and also use for issue diagnoses of non-Pertronix components, is something I also carry. A while back when driving through another state with a friend in his Healey, we had the car stop with a pop at a traffic light and stopped run. Since we were quite a distance from home, even a tow would not be practical or, I expect, easily available. However, we did have a complete points setup, with rotor and distributor cap, and a light bulb for timing. Arriving back at home on the points ignition, we began replacing the cap, and then rotor with no change. At that point we reinstalled the Pertronix to find that it was the faulty component. Yes, we could have done this on the road but, since we were unfamiliar with the area and also loosing light, we agreed it would be prudent to head for home before experimenting. We never found the reason for the Pertronix failure but were will definitely create a diagram for going back to points as we both had difficulty remembering something we had done for decades.

By the way, I also carry a spare head (trigger) for my SU pump for the same reason.

Just a thought,
Ray (64BJ8P1)

 

[Bob_Spidell]

... However, the number of Pertronix ignition failures being experienced by Healey owners

Ray,

Where are you hearing of all the Pertronix failures? I follow this forum and autox mailing list closely, and I can't recall any proven Pertronix failures in years (there were a few many years ago, but the Pertonix people have apparently improved their design and QA). We have them in 5 vehicles--I've had one in my BJ8 for at least 10 years and 50K miles--with never an issue we could attribute to the 'breakerless points;' though it seems they're the first thing everybody blames when they have ignition troubles.

The problem that started this thread sounds like a bad rotor to me; I have had those fail and now carry 4 or 5 spares. And fuel pumps, well, don't get me started.

 

[donbmw]

I have had two Petronix failure but the ignition never completely failed. Every time I have had a complete ignition failure it has been the rotor. Petronix failures have been missing under loads or not firing on all cylinders. Have gone back to points and it seams to run and start better with points.

Don

 

[RAC68]

Hi Bob,

Since the introduction of Pertronix ignitions, I have known of many that have been installed with a small number of failures. However, I have no idea what the cause of the failures are as my Pertronix (on my TR7) has had no problems. With your question, I did a fast search on this web site and found a number indicating problems but only read the title of the thread. Although many Pertronix failures may be the result of issues outside of the Pertronix, it seem to me that the units shows a high sensitivity to ancillary failures or seems to be from the comments of others.

Personally, my TR has had the unit for the past 10 years with no issues (crossed fingers) so, other then my previous post, I have not personally experienced a failure. Don't misunderstand, I like the Pertronix but find the Crane very reliable and should also be considered.

Ray (64BJ8P1)

 

[JAV]

One Pertronix failure nobody has mentioned is where the magnet cam glue has failed and the magnets fall out. Not visible without removing the cam.

 

[Michael Oritt]

Steve--

I have been running a Mallory Unilite in my 100 for about ten years with never a hitch and I use Pertronix units in all of my race cars. Nevertheless you have a point when you say "If the cause of failure is external, such as a coil short, you may destroy your $100.00 replacement as well".

Of course, installing a points set introduces another component--the condenser--that can fail either totally or intermittently and its defectiveness is often easiest ascertained by installing...a new condenser!

Bottomline, if one is willing to take his Healey out for a ride he needs to have a modicum of knowledge and a few spare parts--plus the tools to install them-- to address the most likely failures . Someone either in this forum or on the Healey newsgroup used to say that every ride is a test drive. I'll add that it can also be an adventure into the little or unknown.

 

[Bob_Spidell]

Hear hear. The long Healey trip I take with my BFF is the height of my year (we call them 'The Great Healey Trips'). We never hesitate to take the loneliest backroads--in fact, we make a point of it--and we've done it every year for over 20 years (except for a couple years due to family illnesses). We only got stranded once, when a rebuilt water pump blew its seal (it's a long story). It's amazing how most of the tools you need to maintain or repair a Healey can fit in a tackle box-sized tool box, and (at least) two spare fuel pumps don't take up that much space in the boot. Healeys are simple, rugged cars that can take a beating. They DO take some TLC.

I've never seen a Ferrari, Lambo or even a decent Porsche on the backroads; though last year a McClaren and a Ferrari Scuderia blew past us coming into Lee Vining. They stopped--for some high-fives, I guess--and we putted right by them.

 

[Keoke]

However, the number of Pertronix ignition failures being experienced by Healey owners may make the Crane ignition's higher cost (approx. $10) and external box (easily hidden) something that should be reconsidered as a replacement for the failed Pertronix.

Nope RAC68
That is old world engineering and adds a degree of complexity installing it in the dizzy.
Plus Pertronics failures are few and far between these days.

However, spare parts have been adequately mentioned by others,I carry a spare dizzy with a spare tested pertronics all set up ,

I use an old defective dizzy cap to keep things inside it clean.

I find swapping out a dizzy onah side of the carriageway is easier than changing modules.

 

[RAC68]

Keoke,

It is hard to refute your suggestion that the Crane is old technology as it has been installed in my Healey for the past 20 years without a failure. However, it does have characteristics that may help to promote its longevity. The Pertronix is fully housed within the distributor and, for its simplicity and cost advantage, become the choice of many. However, many of the discussions relating to Pertronix\ ignition-issues seem to suggest heat within the distributor being a major contributing issue.

The Crane optical trigger is the only component installed within the Healey distributor with all other electronics mounted external and, in my installation, separate from the engine for better cooling. This may be the pivotal factor for considering an alternative ignition for a Healey and not for other makes (i.e. my TR7) that enjoy a much cooler engine compartment and distributor environment.

Box mounted on wall passenger foot fire wall

Again, my intent is not to dismiss the Pertronix or suggest its overall design is prone to failure. However, if heat is a major factor leading to a Pertronix failure, then the Healey's engine compartment and distributor could present the environments most prone to accelerating faults.

My thoughts,
Ray (64BJ8P1)

 

[Keoke]

My thoughts,
Ray (64BJ8P1)

KUM-ON Man sound like you in love with that antique thing----------:highly_amused:

 

[RDKeysor]

Not to prolong this discussion that I started, but I have encountered another issue while shopping for a spare/replacement Pertronix. A couple of LU-165 units listed on eBay include a fixed list of proper fitments, none Healeys, and a pull down that lets you identify other cars, in my case a '60 BN7 with negative ground. The answer comes back, and this in red letters, warning that this unit is not correct for the Healey I identified. But the Pertronix business site, upon being given the dizzy in my car, DM6A 40581A, says the LU-165 is the proper unit. The unit now in my car, installed by the restorer likely eight to 10 years ago, bears this on the white label: "Pertronix Carb E.O. D56 2." I haven't remove it yet and am seeking advice on whether the coil could be shorted, endangering a replacement unit. I get a good spark between the coil and the wire to the dizzy but didn't get anything at a plug wire, as described earlier. Checking that again today with a plug grounded. Hope we are all learning something from this exchange. Frankly, I've never owned a car that has had so many things go wrong with it despite the fact that it is just a wonderful car to drive. Blessed that it chose its first failure on the road less than a mile from home and near a friend with a tow vehicle.