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MG Midget and Sprite Technical - Condensers again

Just for the sake of having this in the archives for TurboBob, Allow me to pour forth my tale of woe...

IN April I took a trip in my Bugeye to Toms River, New Jersey, about 2000 miles overall. On the way home, my distributor cap started to track in the pouring rain, so I swapped in my spare. Unfortunately, the trip was a last-minute decision, so the only good spare I had been able to grab was the 123/Mini from my midget, so I had to swap over the whole assembly.

Arriving home, I opted to re-do the Bugeye distributor with new cap, wires, rotor, points and condenser, sourced from Worldwide Auto Parts (of rebuilt Armstrong shock absorber fame). Got it all done and running nicely. A week later I hopped in for a quick drive and it was running abominably. I "knew" the ignition was perfect, so I tweaked the heck out of everything else with no success. Finally took the time to re-do a spare distributor with the points and condenser that I had pulled from the Bugeye after the trip, dropped it in (giving thanks repeatedly for having a LHD Spridget) and suddenly all was well. Spent too much time swapping everything else out first, only to find that the offending party was the brand new condenser. The VOM shows no continuity whatsoever from can to lead. The primary symptoms were that the car would fire weakly, occasionally running nicely for as long as 20 seconds, then dying again.
David "some day I will go pertronix in the Bugeye" Lieb
David Lieb

David
I live by the motto "al new condensers are crap!" ;)
So i either have 123 igintion or a electronic conversion in my cars.

http://www.simonbbc.com/

Do a good one it costs slighty more than points and a condenser but work like a charm!

No need for an expensive pertronix ;)
Onno Könemann

Quite true. All condersers are crap !
Mind you i did have a rotor arm crack once. It completely killed the engine, and i only found it by accident.
I think it may be time to fit an electronic ignitor of some sort. i have one on my 1500 and it is all inside the ditributor. Not like years ago when there was a great big box of electronics to find a home for.
Also it is one less thing to worry about.Especially if you couple it with one of the nice red rotor arms from Distributor Doctor.
S Langston

Quoth David:

"The primary symptoms were that the car would fire weakly, occasionally running nicely for as long as 20 seconds, then dying again."

Precisely the symptoms I encountered years ago before finally tracing the problem to the consenser - and replacing it with a spare one I'd had in the boot all along, during which time the car died several times and was brought home via truck twice.

Gryf "PerTronix" Ketcherside
Gryf Ketcherside

Hey, I have the 123/Mini in my Midget and I have used Pertronix conversions in the past with no regrets. There just happens to be some charm to keeping points and condenser in the Bugeye, perverse soul that I am.
David "no fool like an old fool" Lieb
David Lieb

The only problem with electronic ignition is that if it fails, you're going home on the back of a truck...unless you've got a spare unit, or a dissy with points that you can swap out and time in at the roadside.

If you carry a spare rotor arm, condensor and a few tools, you can get it going again.
Dave O'Neill 2

"All condersers are crap"

Sorry gentlemen, but the above statement is not true. That said, a condenser (capacitor) is most likely to fail very shortly after installation. Once past the the initial burn in period, a capacitor will normally not fail unless acted on by external forces (over voltage, physical damage, etc.). This is why I rarely ever changed the capacitor in the ignition of the old points style ignition systems in our cars. The old maximum, "if it works don't screw with it" applies to capacitors. Cheers - Dave
David DuBois

David,
I thought the saying was, "If it ain't broke, fix it till it is!"
David "back to the old condenser" Lieb
David Lieb

Distributor Doctor does condensors too -
http://www.distributordoctor.com/distributor_condensers.htm

I've yet to have an electronic ignition go on me

points closing yes,

HT leads twice - second time a new set was on my list by I broke my own rule as they 'looked' in so good condition

SU points petrol pump yes(without much warng too)

coil end of HT lead vacuuming loose from coil twice
N Atkins

We are talking about road use here I assume.

In 34 years of driving my sprite, and christ knows how many other cars with points ignition, I have never broken down because of a failed condensor. That is not to say that they dont fail, they do of course, but not as frequently as is suggested.

Its just a capacitor, and as said by David in washingtion, they, like other components follow the bath tub failure rate curve. If fitted correctly (easy) and not subject to incorrect voltage (easy) will have a VERY long bath tub. hence I have never had a failure.

Electronic ignition delivers a very good performance, no doubt about it (if its a good one), but properly setup, so do points ignition. Once put in, unless you NEVER grease the heel of the points, I don't see how they can close up, unless you don't do the screw up tightly enough. If points get pitted as they will, a flat file sorts them out. If you can see well enough to see your points and the gap between the faces, you can guess that gap well enough to get you going again.

How are you going to fix an electronic setup?

Condensors are pretty much fit and forget for many years.

I've got an ignitor siting in garage. Maybe I'll use it one day, but haven't found the need. Wanna buy it cheap?

As for HT leads, if you use decent copper leads, what's to go wrong? Even if the insulation is cracked, which takes years, you just dont let them touch anything, or eachother, and they will also get you home. Whack a bit of insualation tape round them, wipe the oil off 'em etc.

"coil end of HT lead vacuuming loose from coil twice" What? Don't follow this at all. What Vacuum do you mean Nigel?
Lawrence Slater

Hi All

This is s fairly recent problem and seems to affect new condensers. Sadly old condensers slowly die. We have started making out own replacement external condenser packs and have some out on test. Hot VeeDubs and race cars.

http://www.britishcarforum.com/tikiwiki/tiki-index.php?page=Condenser+Failure+in+Conventional+Ignition+Systems

Peter
P Burgess

Swiftune do a fantastic reliable condenser.

http://www.swiftune.com/Category/68/ignition.aspx

We also stock them for our Australian enthusiasts...

Mark.
M T Boldry

"the bath tub failure rate curve" only works for complicated combined electro mechanical installations, not for electronics.
Alex G Matla

"the bath tub failure rate curve" only works for complicated combined electro mechanical installations, not for electronics.

No it doesn't. You can apply bath tub curves to pretty much anything. It either fails at the beginning of it's designed life, or at the end, with a mostly reliable period in between.

Here's a definition for you, pulled from the web.

Bathtub curve - Common term for the curve (resembling an end-to-end section of one of those claw-footed antique bathtubs) that describes the expected failure rate of electronics with time: initially high, dropping to near 0 for most of the system's lifetime, then rising again as it "tires out".

Here's another.

Bathtub Curve = Graphical representation of the expected failure rates of a component. So called because of its similarity to a bathtub.

It's nothing more than an over simplified form of expressing, when a component might be expected to fail.

Please Explain your statement that it does not work for electronics, either passive or active.

Lawrence Slater

Peter -

That was an interesting read, thanks! Wish I still had my old capacitor so I could take it apart and check for arcing as the article described. I seem to remember flinging it somewhere...

-:G:-
Gryf Ketcherside

Peter,
are the Distributor Doctor condensers to be recommended too -
http://www.distributordoctor.com/distributor_condensers.htm

Lawrence,
sorry missed your questioned – I got into a habit of checking the HT leads were firmly seated because of this at the coil end the lead and connection inside the cap actually lifted up as I’d been pushing down on the cover cap and because I hadn’t fully burped the cover there was a ‘vacuum’ or pressure or back pressure or whatever that cause the cap to go down and lead up – there clear as mud
N Atkins

Here is an intresting thought...

Are all condensors created equal ???

When I thought I was goimg to midget 50, I got a spare points ad condensor for just incase, bit I also found 2 extra condensors to my mallory duel point distrubutor

My question is ... Can I use my mallory condensors with the lucas points.... They look almost alike, and same size, but have a reputation of being fail proof....

So could we use the mallory comdensors in place of the lucas condensors ???

Prop

Prop

Good question Prop.

The points are just a switch, so the condensor will be doing the same job whether in a Lucas or Mallory distributor.
Dave O'Neill 2

Here you go Prop, follow this link. All you need to know (ish), about points ignition.

(It's from a Triumph Herald site actually, but hey, same difference).

http://herald-tips-tricks.wikidot.com/ignition:basic-points-type-inductive-discharge-ignition-syst
Lawrence Slater

Ah right Nigel, I get your drift. When pushing the coil end of the HT lead into the coil, the HT lead probably moved back, relative to the lead sleeve or cover, thus making it appear as if the HT lead had been pulled backwards (vacuumed).

I was imagining so much power being developed in your engine bay, that somehow a vacuum was being created, akin to a black hole, that was hoovering up all your bits and pieces that are not actually bolted down. :)
Lawrence Slater

PMSL ;o)
Dave O'Neill 2

Hahaha...in my case the engine runs so fast that the exhaust leak creats the vacume vortex..

Interesting thought nigel, I did the same thing the other day with the new coil,and lomger coil wire, I just assumed the coil wire conmector needed more expansion for a tighter lock on...

According to your thought perhaps it would be better to NOT plug the the wire in 1st then slide the boot down into place but rather do it as one Step procedure....the wire and the boot at one time.

Good call nigal,i think you got good argument

Prop
Prop

Hi Nigel

I missed your thread above. We have had no problems with any of the DizzyDocs stuff.

Peter
P Burgess

PMSL....

NOW that is a good response, I had to look that one up

.
Prop

Hope you've changed since :P
Lawrence Slater

cheers Peter

Prop, Lawrence,
I'm mainly saying I was an idiot, twice, I know if these caps are tight that they need burping but forgot to do it

easy to find as car wouldn't start but you car hear arcing

I must remember not to let the weight of my shadow to fall on things :)
N Atkins

I recall a while back investigating purchase of a condenser online or at one of the parts shops... I forget which. But I found several different ratings listed, and getting a suitable one for the Midget didn't seem so cut-and-dried. I thought that one type would work for pretty much everything, but apparently not.

Funny, I had to get a new wireless router for home the other day when my old one went intermittent, and when I opened the case I found a swollen capacitor that was quite probably the cause of the problem. A few years back we had major issues with Dell PCs here in the school district where I work, due to motherboards and power supplies bonking with failed capacitors. It was in the tech news back then, and if you Google "Dell capacitor failure" you still get plenty of hits.

Anyway, you get the idea that capacitors in general can be rather iffy. Or at least the cheap ones can, which was most likely the problem in both cases... Midget and PCs.

-:G:-
Gryf Ketcherside

I dream of a day and can imagine a planet where mankind and compasitors can create world of peace and harmony.....could that have been the real message of the beetles...

drugs just got in the way....haha


Prop
Prop

Jeez, what are you smokin man? Can I have some?
Lawrence Slater

This thread was discussed between 16/07/2011 and 22/07/2011

MG Midget and Sprite Technical index

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