Engine dies but restarts easily

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Hectork
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Re: Engine dies but restarts easily

Post by Hectork »

Changed the coil on Sunday (ESM Lucas Sport coil). Ran it at idle on the drive for 45 minutes, then went for a spin around the block. 75 minutes running in total, didn’t die.
Hoping that’s it. Will have a proper drive when lockdown ends and report back, but the signs are good!
liammonty
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Re: Engine dies but restarts easily

Post by liammonty »

Hectork wrote: Mon Jan 11, 2021 9:17 pm Changed the coil on Sunday (ESM Lucas Sport coil). Ran it at idle on the drive for 45 minutes, then went for a spin around the block. 75 minutes running in total, didn’t die.
Hoping that’s it. Will have a proper drive when lockdown ends and report back, but the signs are good!
Well done! I've had a few coils fail over the years and have had similar symptoms with at least one of them. Silly of me to to thinkk of mentioning it when you first posted. As the new ones aren't great quality (putting it mildly) I would be tempted to keep a spare in stock. I carry barely any spares in my Minor (unlike some who seem to carry all sorts) but that's one part that you'd do well to have a spare of. Lucas ones nowadays aren't great either, unfortunately.
kevin s
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Re: Engine dies but restarts easily

Post by kevin s »

New one on ours lasted less than 1000miles, I don't think the modern ones are up to the vibration of being mounted on the engine.
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geoberni
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Re: Engine dies but restarts easily

Post by geoberni »

kevin s wrote: Mon Jan 11, 2021 10:22 pm New one on ours lasted less than 1000miles, I don't think the modern ones are up to the vibration of being mounted on the engine.
My thoughts exactly. The broken connection inside my Coil when I opened it up was classic fracturing of a solder joint, easily caused by vibration of the unsupported, very thin connection.
I moved the Coil to a more traditional location, on the rear bulkhead, snuggled between the wiring loom and the starter cable. :wink:
Basil the 1955 series II

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myoldjalopy
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Re: Engine dies but restarts easily

Post by myoldjalopy »

I don't know why they moved the coil from the bulkhead, where it was positioned at an angle a short distance below the control box, to above the dynamo during SII production. I suppose there must have been a reason........
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Re: Engine dies but restarts easily

Post by pgp001 »

My coil was originally mounted on a bracket above the alternator, but was causing problems with it getting too hot.
When you think about it when positioned there it gets all the heat from the being next to the engine and also a a blast of hot air coming at it through the radiator. Not to mention the vibration issues as well.

My solution was to move it lower down in the engine bay and fix it to the inner wing with a vertical bracket.

https://www.ebay.co.uk/itm/Chrome-Ignit ... SwdytapdTS

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kevin s
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Re: Engine dies but restarts easily

Post by kevin s »

Pretty much what I did as well.
rps20200530_171953.jpg
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this was how the coil had failed.
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I think the wire was supposed to be a length of flexible braid but the solder had made it completely rigid.
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geoberni
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Re: Engine dies but restarts easily

Post by geoberni »

kevin s wrote: Tue Jan 12, 2021 9:14 pm
I think the wire was supposed to be a length of flexible braid but the solder had made it completely rigid.
Same place that mine broke, except the braid connection remained in place:
viewtopic.php?f=11&t=69837&hilit=Coil&p=637860#p636467

I didn't accurately describe where I relocated mine, when I posted yesterday.
Here's a photo to show it.
I used the bolt for the cable clip and the other hole was already there in the bulkhead. I just needed the large washers to compensate for the size of the slots in the mounting bracket.
Obviously not a location available to those with the elephant trunk heater duct. :wink:
20210113_112414.jpg
20210113_112414.jpg (909.97 KiB) Viewed 1200 times
Basil the 1955 series II

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Hectork
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Re: Engine dies but restarts easily

Post by Hectork »

This is the gift that keeps on giving!

25 mins in today, same old fault even though I have the brand new coil on. New coil was cool to touch. The coil is mounted on the drivers side inner wing below the heater fresh air hose. All wires to the coil looked fine.

Everything looked normal under the bonnet, other than the high tension lead inner connector at the distributor end looked a bit corroded. I had no sandpaper so I gently scraped it clean with a small screwdriver. Made no difference.

Put oil in the carb dashpot just to rule that out. No air lock in the fuel tank.

Couldn’t get it to start so left it for 25 mins. Bloody cold, should have had two pairs of socks on!

Started on the button after the wait. Six miles from home, at low revs and made it all the way without it doing it again.

Flummoxed, particularly since it worked fine last time I tested it. Can it really be the coil if it runs fine then cuts out exactly the same as the old coil?

Condenser? Carb?

I have an electronic ignition unit from ESM that I got when the fault first appeared. Going to stick that on so I can rule that out too.

Cheers
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Re: Engine dies but restarts easily

Post by oliver90owner »

Flummoxed?

Have you checked for a spark at the king lead immediately after it has stopped? Have you checked for a spark at the plugs, if there is one at the coil? What colour is the spark, if there is one? How strong is it (what size air gap will it jump) if there is a spark?

Do this! It WILL sort out if the problem is with the coil (or wiring to it) or further along the ignition circuit or even if it is nothing to do with the ignition at all! Until you do this you WILL be effectively ‘flying blind’.

Simple diagnosis costs nothing. It could well have already saved you the cost of a coil, for a start.
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Re: Engine dies but restarts easily

Post by liammonty »

Agree regarding the points suggested by Oliver. You’ll need to be systematic regarding tracing the fault, as described. It could be down to any component in the ignition system.

I had this recently with a faulty rotor arm on my Wolseley Six and as with many similar electrical issues, it only become evident once the car had warmed up, when it caused the car to grind to a halt.
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Re: Engine dies but restarts easily

Post by Bigrob »

I had a similar problem with a metro I had.


It would happily start cold or hot no problem.


But every so often I'd be driving and it would just die.

So I replaced distributor, coil, leads and plugs.

And although it ran better, it still happened.


So I stripped and cleaned the carb, replaced the throttle cable and it never happened again.


I never could figure it out
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Hectork
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Re: Engine dies but restarts easily

Post by Hectork »

Oliver90owner - I do appreciate the advice and that makes compete sense, but I can’t test for sparks after the fault has arisen unless I can turn the engine over and get under the bonnet at the same time? I don’t have a starter solenoid with a push button on it, and the Missus doesn’t want to come out and play breakdown with me! I guess it would work if I patched a wire from the battery to the solenoid spade connector (starter wire)? Clearly would need some concentration to do that and check for sparks too.

It’s Winter and we’re still bored in lockdown, so I’m going to replace the distributor and rebuild the carb anyway. The carb hasn’t been touched much in the four years I’ve had the car, so it’s probably time well spent...

I’ve got a new king lead too, will stick that on.

Will see if that makes any difference. Yes, I know, I am flying blind....it’d probably be less fun if I knew what I was doing! 😂
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Re: Engine dies but restarts easily

Post by myoldjalopy »

Well, if you are 'flying blind' then I would at least swap the rotor, as hinted at by 'liammonty'. I once had similar intermittent problems which turned out to be the rotor arm breaking up.
Hectork
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Re: Engine dies but restarts easily

Post by Hectork »

Thanks myoldjalopy, I’ve got an electronic ignition distributor to try out,
oliver90owner
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Re: Engine dies but restarts easily

Post by oliver90owner »

I can’t test for sparks after the fault has arisen unless I can turn the engine over and get under the bonnet at the same time?

The coil develops a high tension spark as the magnetic field collapses around the secondary winding. That magnetic field is produced by the current in the primary circuit. It collapses when the current is cut off (by the contact points when the engine is running). It will also collapse by disconnecting a connection at the coil.

Disconnecting the coil is very simple and an easy operation. I suggest you try it to understand that it does work, so that you are prepared for any time a similar scenario occurs.🙂 The distributor on the engine might carry out that operation over 50 times every second, but you don’t need to do it quite so quickly.

A little more time consuming method, but usually carried out in a sufficiently short time, would be to remove the distributor cap and open the (closed) points with a suitable tool (while the ignition switch was turned on, of course).

You neither need to use the starter motor nor your wife (or anyone else) to come out to play with you!
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Re: Engine dies but restarts easily

Post by kennatt »

You don't need to spin engine to test for spark . when it stops,take cap off dizzy,make sure points are closed,push car about in gear to close them.Pull King lead off dizzy and hold close to engine block.With ign switched on. Flick points open with insulated item,screwdriver bit of platic etc and if coil is ok you will get a good loud spark .IF ok connect up and remove plug and do the same and watch plug gap.

Didn't read all of last Oliver, So as above.
ManyMinors
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Re: Engine dies but restarts easily

Post by ManyMinors »

Or......Use your starting handle to turn the engine!
Hectork
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Re: Engine dies but restarts easily

Post by Hectork »

Brilliant. Yes, even I can do that. Thanks very much, will try next time.
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Re: Engine dies but restarts easily

Post by ManyMinors »

I find the starting handle very useful for checking the contacts - and the valve clearances too. Sometimes even for starting the engine :wink:
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