Ignition coil

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RichardGibson
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Ignition coil

Post by RichardGibson »

HI
I thought I would post this to see if anyone else has experienced the following phenomena:-
I have just fitted a new coil to my mark 2 Interceptor in a continuing effort to improve running and do away with the occasional coughing and spluttering (car is not yet old enough for a free flu vaccination). I had replaced everything except the coil up to now, plugs, point, condenser, plug leads, dizzy cap, rotor arm, fuel filter and even the fuel pump. The car was tuned twice and running OK but still not right, also cold starting is a problem. So one last thing to replace the ignition coil.
Received one today from Robeys and fitted it at lunch time all good.
When I fired the car up it took a few churns of the starter motor but then fired and ran nicely. However I could hear a cracking noise and on looking in the engine bay I noticed an occasional spark tracking between the centre electrode and the negative terminal. I stopped the engine and taped up the terminal with insulating tape.
On starting the car again, this time first turn of the key, I noticed a spark tracking between the centre electrode and the positive terminal on the coil. Engine off again and I taped up this terminal. Started again and no spark tracking at all and engine running sweetly.
Has anyone else experienced this issue or has anyone an idea as to why the spark should track between a terminal and what appears to be insulation around the centre electrode. I contacted Robeys but they had not experienced this and asked me to check for a crack in the insulation, I did and could not see one.
Any help out there?
Regards
Richard
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slotcarone
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Re: Ignition coil

Post by slotcarone »

Make sure you did not cross up the + and - terminals on the coil. If not put the old coil back on and see what happens! :)
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RichardGibson
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Re: Ignition coil

Post by RichardGibson »

Hi
Definitely did not cross the terminals.
The coil seems to be working fine now that I have insulated the two terminals.

Richard
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Steve Payne
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Re: Ignition coil

Post by Steve Payne »

What make of coil is it?

Steve
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RichardGibson
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Re: Ignition coil

Post by RichardGibson »

Hi Steve

Do not know the make of the old coil other than it is marked "made in USA".
New coil is supplied by Martin Robey and is manufactured by the prince of darkness Lucas.
Once I wrapped each terminal in insulation tape there was no issue and the car ran better than when the old coil was in position.
I think my next job is to gradually remove the insulation tape from each terminal checking at each stage.
It could be that the leakage is from the centre electrode to the negative terminal due to the centre electrode not being fully sealed.
Regards
Richard
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jvcarrier
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Re: Ignition coil

Post by jvcarrier »

I would check the leads are all pushed home correctly. The spark is following the path of least resistance so possible there is a high resistance point to the distributor or out to the plugs?
RichardGibson
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Re: Ignition coil

Post by RichardGibson »

This was pretty much my thinking, I feel that the leakage is from the connection from the coil to the dizzy cap which admittedly does not feel like it pushes home properly, on other cars I have owned this usually pushes home very firmly . The whole ignition circuit has been replaced with new parts so a failure is unlikely.
I posted this because I have never experienced this happening on any car I have worked on.
Richard
RichardGibson
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Re: Ignition coil

Post by RichardGibson »

Hi All
I do believe I have now found the reason for the sparking between the the feed to the dizzy cap and the two terminals on the coil.
Consequently I feel a bit of a fool.
I was sitting reading when suddenly I had an epiphany out of nowhere and nothing to do with my reading matter.
I rushed out to the garage and checked the ends of the lead between the coil and the dizzy cap after removing the lead.
It had always bothered me that the lead did not fit tightly onto the end of the coil.
Sure enough, the ends of the HT lead between the dizzy cap and the coil are slightly different in size.
I turned the lead around and bingo the lead to the coil fits as expected snugly into the coil and also to the dizzy cap.
No more external sparking and the car started better, still a bit of a running issue though when cold, cuts out while driving occasionally.
Car runs fine when warm.
Thanks
Richard
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Grant
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Re: Ignition coil

Post by Grant »

RichardGibson wrote:Hi All
I do believe I have now found the reason for the sparking between the the feed to the dizzy cap and the two terminals on the coil.
Consequently I feel a bit of a fool.
I was sitting reading when suddenly I had an epiphany out of nowhere and nothing to do with my reading matter.
I rushed out to the garage
Richard
:lol: :lol: .. I have done exactly the same thing before Richard with something niggling me in the back of mind.. I've even woken up in the night before and suddenly thought about it and had a solution... so your not the only oneImage.. it's because we are all Image
Glad you sussed it thoughImage, well doneImage
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