sudden ignition failure

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myoldjalopy
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Re: sudden ignition failure

Post by myoldjalopy »

Indeed! Which is why starting with 'is there a good spark at the king lead?' is an excellent starting point for ignition problems. If there is, then you know to look at things like the dizzy cap, the rotor arm, the plug leads and plugs. If not, then you can ignore such things and look back through the coil/points operation/connections etc.
Come to think of it, there really ought to be one of those binary choice ignition problem flowcharts as a sticky to this 'electrical' section of the discussion board.
youngb506
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Re: sudden ignition failure

Post by youngb506 »

The carbon bush in the cap looks fine and it springs back and forth easily. I'll have another look at the spark from the king lead tomorrow and report back.
youngb506
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Re: sudden ignition failure

Post by youngb506 »

When the end of the king lead is held quite close to the engine block there's a regular orange spark. If Im using my multi meter correctly, there's a resistance of 1.5 ohms in the primary circuit (measuring across the two contacts) but I can't get a reading on the secondary circuit measuring from + to ht output socket (or indeed from - to socket in case Ive misunderstood this in my positive earth car. ). Does this mean the coil is at failt?
pgp001
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Re: sudden ignition failure

Post by pgp001 »

An orange spark is not good, do you have a spare coil you can try ?

There is a Youtube video showing what kind of spark you should be seeing.
https://www.youtube.com/watch?v=sjQd2p0lakw

This video shows how to test the coil in isolation, so you do not have points or condenser to worry about.
https://www.youtube.com/watch?v=rJYJ3KvPhhY

Phil
oliver90owner
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Re: sudden ignition failu

Post by oliver90owner »

If you are using your multimeter properly and it is working properly the primary resistance would be more appropriate for a 6V system! Coil would draw about 8A which is about twice it should do. Do you have a 10A setting on your meter? (better to put a high power resistance in series, to avoid burning up the meter if it actually draws more than 10A, so the substitution may be the safest option).
youngb506
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Re: sudden ignition failure

Post by youngb506 »

Thanks for the video link. Even looking at my spark in the dark, the one in the video is much bluer and much stronger. Also, my spark will only jump a 1/4 inch gap.
youngb506
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Re: sudden ignition failure

Post by youngb506 »

"It's never the coil" but if this has gone, it's the second one in less than two years. Is there a known problem with new coils. The last one was Lucas ( made in Shanghi, I think) and this one is a more expensive NGK
myoldjalopy
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Re: sudden ignition failure

Post by myoldjalopy »

The mantra "Its never the coil" refers to the good old 'proper job' ones. Many on here have reported failure of the new varieties. If it is indeed the coil that has failed, I would look out for a known good old one, at an autojumble or even post in the 'wanted' section on here. I have an 'old' one on my car, and an 'old' spare which I have never needed in the last 19 years of owning my current Minor.....
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mobylette
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Re: sudden ignition failure

Post by mobylette »

I believe the club spares has some old genuine Lucas ones, also the Bosch coil for Beetles are meant to be good:

https://www.justkampers.com/043-905-115 ... -1979.html
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liammonty
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Re: sudden ignition failure

Post by liammonty »

I'd second that re the Bosch coils - I've used them on my T2 VW and on one of the Minors over 15 years without issue.

Also agree regarding the 'old' coils - however, bear in mind that these are now decades old, so may well fail too! I accept that years ago, it was seldom the coil that failed, but Roy's insistence that it was 'never the coil', even to me on the day that I'd been stranded on the side of the M69 for 2 hours having suffered a coil failure, did grate with me a little ;-)

As with all the other electrical components, the coil is definitely worth checking in the case of suspected electrical issues!
Shropshiremoggie
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Re: sudden ignition failure

Post by Shropshiremoggie »

My 1970 Minor 1000 ( in the family since new ) and my 1975 ( bought in 1982 ) Landy exhibited the same symptoms . In both cases it was the coil . In both cars the vehicle had the original coil . May not be the case here but they do fail !!!!
myoldjalopy
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Re: sudden ignition failure

Post by myoldjalopy »

Every component of the car will fail eventually, including coils - ultimately, it is simply a matter of time. Personally, however, in over 34 years of driving Minors I have never had a coil fail........yet. Nevertheless, I have suffered countless other failures - from a blown head gasket to a faulty rotor arm to a broken crankshaft to a snapped fan belt (which, incidentally, ripped out some headlamp wiring and sliced through a radiator hose at the same time! :o )
But we now eagerly await the answer to the present situation!
shoebone
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Re: sudden ignition failure

Post by shoebone »

The late Roy also used to say that when a new coil fixed the problem, its not because the old coil was bad but the connectors had probably corroded over the last few decades and sliding them on to a new coil would clean a new electrical path and give good conductivity. I think its always a good idea to clean all electrical connections as part of early fault finding, this includes earth points.
youngb506
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Re: sudden ignition failure

Post by youngb506 »

It's always the coil! At least in my experience of the last three years. This time Ive gone for the Lucas sports coil which was cheaper at ESM than the regular Lucas coil and they assured me they'd had no returns. I've gone for the push in ht terminal rather than the screw in because it's a bit more convienient. After a week and a half, the engine started the moment I'd pulled the starter.

The NGK coil that was in the car lasted about 10 months. I'm looking for the receipt now to claim my money back. The previous standard Lucas coil lasted about the same time.

The coil was the last thing I thought of checking. I had a cheap multi meter for Christmas and if it wasn't for that, I'd still not have thpught it could be the coil.

I'd begun to think that I'd messed up on installation of the points or fogotton if the capacitor lead and low tention should touch the points spring or be insulated from it.

Many thanks for everyones help and suggestions. This message board almost makes the 40% hike in MMOC membership fees over the past few years worth it!
pgp001
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Re: sudden ignition failure

Post by pgp001 »

I think the “It’s Never The Coil” saying that we all seem to find on here, should be somehow linked to the more up to date posts where “It Is Always The Coil”

It seems to be a trend lately that some components that we all suspected to fail the least, are now made so poorly that we need to revise our way of thinking out solutions to these problems. Nothing should be taken for granted as being OK just because it has already been replaced.

Glad my suggestion turned out to be the solution for you.

Phil
myoldjalopy
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Re: sudden ignition failure

Post by myoldjalopy »

Phew! Glad its sorted. Thanks for coming back. I think the (unspoken) end to the mantra is "Its never the coil - except when it is!" :lol:
At least now you have the car running again and can be confident that the Distributor Doctor components you have fitted are reliably made 8)
oliver90owner
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Re: sudden ignition failure

Post by oliver90owner »

Good to have it sorted, but if only you had checked out the components before rushing in and replacing parts ‘willy-nilly’. You would have found the fault in next to ‘no time’ and not wasted a week and a half on a simple component failure.

Lesson learned?
les
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Re: sudden ignition failure

Post by les »

The trouble is, and understandably, not everyone is up to this precise ‘analysis’ approach, so go a considerd substitution option. They may be perfectly able people but perhaps not as scientifically adept as others. We all approach thing differently for whatever reason.

liammonty
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Re: sudden ignition failure

Post by liammonty »

Well done for getting it sorted. You increasingly have to expect the unexpected with ‘quality’ new components. I’m not an advocate of carrying many spares, even though I often use the Minor for long trips. One of the very few parts I do now chuck in the boot, though, is a coil, as I’ve been stranded twice on the side of the motorway over the past 10 years due to them failing. When I experienced yet another failure last year on the M5, I was able to get going again after 5 minutes, rather than waiting hours to be recovered.

And before anyone suggests that there must be an underlying issue with the electrics on the 2 cars this has happened to me on - there isn’t :wink:
mowogg
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Re: sudden ignition failure

Post by mowogg »

I have had 2 lucas sports coils a few years ago Both failed in service after a few months. I would not advise using these.
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