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It was the Coil or so we thought!

Posted: Sun Jun 16, 2013 12:51 pm
by gtt1951
Car conked out, yesterday (Saturday), on the way to the Internaltional Rally, in the middle Woodstock. Within moments a black saloon pulled up and I siad I shoild be OK as it is probably the Su pump contacts (had some problems on the Thursday.
Well - it wasn't the pump contacts (but there may have been a secondary issue with the pump - bashing it helped).
By this time some more very friendly and helpful Morris Men (of the non-dancing variety) had pulled over - a blue Saloon, a blue Tourer (both could have been "dove grey") and an Almond green Traveller.
The Tourer driver whose name I have forgotten, got out a test bulb and lead and a manuel and did a diagnosis which pointed to the ingnition electrics - I wasn't getting a visible LT spark (nor a HT spark using one of his spare plugs).
We took the coil off his car and tried in in mine. Showed up that the LT coil part of my coil had gone open-circuit.
Diagnosis - ITS THE COIL - to which I replied, "but its never the coil" adding Roy, provision that it never is the coil if you are carrying a spare - I wasn't. The Saloon driver did have a spare coil, but it was of the screw in type and my wiring was for a push-fit.
By this thime the connector on my HT lead to coil had fallen apart!
Then along came Matt, the Young Members Register (hot from the MOT in France) in his Tourer - and he said those magic words "I've got a brand new spare Lucas coil in the car" and it was a push fit.
On that went and the engine fired up.
Whilst we were putting the "test" coil back in the 1st Tourer, my engine died. The "broken" remains of the connector had come loose again. Not to worry crimped it down with pliers and hoped that there would be someone selling appropriate items at the Rally. We made sure the 1st Tourer got started and he went on his - Many thanks to you - I forgot to switch off my CarCam, so managed to lift this frame - so here is a picture of a bit of you.[frame]Image[/frame]By this time we were down to 3 cars, Tourer No.2 (Matt) and the other Traveller (also name forgotten - I'm terrible!), But here is a captured frame (thank you too) -
[frame]Image[/frame]
Next picture shows us about to leave the roadside and it was decided that we go in convoy, with me in the middle, in case something happened again[frame]Image[/frame]
Finally got to the Venue and went in search of sellers with spare coils and HT leads. The plan was to buy 2 coils, one to replace MAtts and as spare for me (my orginal coil in pic below)[frame]Image[/frame]
Found a coil seller (Roy's Spares), but what he told me caused concern. He said that all new coils have to be mounted vertically as they will fail if mounted horizontally in the tranditional location on top of the dynamo - so I only bought one of them.
Finally found Matt and recounted what I had been told, so Matt requested his "loan" coil back (now with some scrape marks) and I went to take his one out and adapt my mounting to take the new coil in its vertical position[frame]Image[/frame]
At this stage I only replaced the HT lead to coil, the rest to be done at home - wise decision as I couldn't get the screw for No. 4 lead out. It is currently soaking with some WD40 down the recess (I would have used PlusGas, but my spray can doesn't have a plugin nozzle tube, like the WD40, so there is no fine control).
Got home safely. Will now also be replacing the fuel pump with the spare I was actually carrying, which I had done some work on previusly (new contacts etc).
Hope nothing mechanical or electrical goes wrong on the Traveller at 60, that I will be attending!

Thanks to all the people who stopped and helped,

George.

Re: It was the Coil!

Posted: Sun Jun 16, 2013 2:11 pm
by lambrettalad
love the snazzy leads :D

Re: It was the Coil!

Posted: Sun Jun 16, 2013 4:20 pm
by gtt1951
Alex, I'm afraid that they were the "donor" ones I took of an old Dizzy, that I had in my "spares", when I was working on the Traveller engine last year and they are going to come out and be replaced by black silicon ones, like the HT coil lead.
It'll all be plain boring black soon.
The red and blue ones were made by Wipac and I think the plug caps were "suppressed".

Re: It was the Coil!

Posted: Sun Jun 16, 2013 9:47 pm
by bmcecosse
Clean up the contacts on that original coil and then let's see a meter test on it. There were so many other things wrong with your car - I seriously doubt it WAS the coil..... You changed /moved so many things.....it just happened to come together again when you fitted the other coil.... :roll: I wouldn't buy anything from 'Roy's Spares'.......blimey! :oops:

Re: It was the Coil!

Posted: Sun Jun 16, 2013 10:54 pm
by gtt1951
I also bought a "pre used" cleaned up and tested coil from another trader (£5) - he threw in another used coil (untested) free of charge.
The only things I had to attend to, recently, were the fuel pump and (Saturday) the ignition - hardly "so many other things wrong".
When I got the coils home, all showed a continous connection (using a multi-meter) between the + and - terminals. The "free" one was showing some resistance. My faulty one was included in this test and was showing Zero resitance between the + and - terminals (but it was cold by this time).
I will clean up the Lucar connectors on my original coil and will test it out again on the car, together with the other two coils.

My concerns are about the fitting orientation and the underfilled oil reservoir of "new" coils - anyone have any more info on this?

Re: It was the Coil!

Posted: Sun Jun 16, 2013 11:01 pm
by bmcecosse
The 'so many' refers to the doubts about the fuel pump - and loose/broken connections at the HT leads etc. Don't get me wrong, just sometimes it IS the coil. My catchphrase is there to make folks think - and not just automatically blame the poor old coil. It really is (almost) never the coil....... A good coil will show 3.2 ohms between the two terminals. If faulty - it will show 'infinity' or at least a few megohms......

Re: It was the Coil!

Posted: Sun Jun 16, 2013 11:15 pm
by smithskids
Whats all this rubbish about fitting the coil vertically, it should work in any position !!! :(

Re: It was the Coil!

Posted: Mon Jun 17, 2013 8:15 am
by Trickydicky
GTT1951, don't take this the wrong way but as you say you had a few issues before setting out for the rally, I would had been giving the car a very good service and check over before setting out and as Roy has said many times, carry the essential spares.
On thing I was taught many years ago is the 6 P's, proper perpetration prevents p*** poor performance.

Re: It was the Coil!

Posted: Mon Jun 17, 2013 8:49 am
by gtt1951
bmcecosse wrote:The 'so many' refers to the doubts about the fuel pump - and loose/broken connections at the HT leads etc. Don't get me wrong, just sometimes it IS the coil. My catchphrase is there to make folks think - and not just automatically blame the poor old coil. It really is (almost) never the coil....... A good coil will show 3.2 ohms between the two terminals. If faulty - it will show 'infinity' or at least a few megohms......
Roy, using an old Avo Mk7, I checked the coils that are out of the car, £5 spare coil is showing 4 Ohms, my original (now cold) is showing 3.5 Ohms and the "free" spare is showing 500 Ohms!
Haven't got time to check the "Roy's Spares" Lucas DLB 101 coil, currently fitted to car, as I'm supposed to be on my way to work (still at home typing this!).

And, Trickydicky, I did do some prep work as the only problem I did diagnose was the pitted contacts on the SU fuel pump on the Thursday before travelling. I was carrying a spare (working) SU pump with me, but not a spare Coil, together with a full tool-kit.
Update later (got evening Welding class to go to after work).
Regards, George.

Re: It was the Coil!

Posted: Mon Jun 17, 2013 11:42 am
by bmcecosse
So - your old coil is perfectly good at 3.5 ohms.... It wasn't the coil after all! The 500 ohms coil - well - put it on ebay or throw it away to avoid trying to use it some time in future. The 4 ohm coil is fine too.

Re: It was the Coil!

Posted: Mon Jun 17, 2013 1:43 pm
by gtt1951
But Roy, it definitely was not working on Saturday, the teminals were tested using a car bulb and wire from the "+" terminal to engine earth (thermostat cover on a -ve earth car) - lit OK and then from the "-" terminal to same location and bulb did not light.
My coil was quite hot - could this have caused a temporary failure?
There was definitely no LT spark at the contact breaker points in the Dizzy. We did the same test with the donor coil connected to my car and it showed up OK on both terminals. Put my coil back in circuit and it didn't want to know.
This morning's AVO readings were taken on a cold coil.
I will try my original Delco coil back in the car and run the same tests whilst cold.
George.

Re: It was the Coil!

Posted: Mon Jun 17, 2013 1:50 pm
by bmcecosse
The light would not light up if the points were closed at the time...... or perhaps because of the 3.5 ohm resistance. Coils don't get 'temporary' failures - they either work - or don't work - but terminals and wire connections can be corroded/loose etc. Coils get hot if the points gap is too small - or the car is standing with ignition ON and points closed. It will be fine - put it back on the car.. Changing the coil often 'seems' to work, simply because the terminals/cables etc are disturbed.

Re: It was the Coil or so we thought!

Posted: Mon Jun 17, 2013 2:40 pm
by gtt1951
Thanks Roy,
In light of all this, I've ammended the subject line. Regards, George.

Re: It was the Coil or so we thought!

Posted: Mon Jun 17, 2013 4:01 pm
by bmcecosse
You need to put the coil back on (or at least connect it up temporarily) just to see if it works.... I suppose it's possible there could be a bad internal connection giving an intermittent fault. Let us know how it gets on! At least you have a few spares now - and they didn't cost a fortune...

Re: It was the Coil or so we thought!

Posted: Mon Jun 17, 2013 5:03 pm
by gtt1951
The brand new one from Roy's Spares cost £16.96 + VAT - it was the "middle" quality one.

Re: It was the Coil or so we thought!

Posted: Tue Jun 18, 2013 4:55 pm
by Matt
You mount them vertically because the new ones have less oil in and an air bubble :o This exposes some of the wires inside to the air, they get hot and burn out.

What that means is that you have still mounted it wrongly... the terminals need to be at the bottom.

Re: It was the Coil or so we thought!

Posted: Tue Jun 18, 2013 6:04 pm
by gtt1951
Thanks Matt,
Mr Roy (who sold me the coil) said they had to be mounted upright (like what he had on display). There were no instructions in the box and I think we all need to have a definitive answer as to the plight of modern coils and which way up they should go. If I mount mine "upside down", then the wiring loom may need to be unravelled for the 2 Lucar connectors to reach the "top" of the coil at the new "bottom" and, similtaneously, for the Dynamo connectors (same loom) to still connect to the dynamo.
Alternatively, I'd have to fit in "extensions", which means even more connection points that can then go wrong through future corrosion :(
What with the fact I also need to try out each coil, I now have, in the car and research coils on the Internet, even more of my evening is going to disappear :oops:

Re: It was the Coil or so we thought!

Posted: Tue Jun 18, 2013 6:06 pm
by MarkyB
I don't think any coils are full of oil, even original Lucas ones.
How about mounting it on top of the dynamo so the vibration of the engine keeps the oil splashing around and cooling every thing?

Re: It was the Coil or so we thought!

Posted: Tue Jun 18, 2013 6:08 pm
by bmcecosse
My coil is upright - on the inner wing, pointy end up. The original wires seem to fit just fine. This removes the coil from engine heat and vibration.

Re: It was the Coil or so we thought!

Posted: Tue Jun 18, 2013 10:07 pm
by gtt1951
OK,
We have 2 people that say mount the modern coil upright, 1 person that says mount it upside down, I've seen underbonnet photos of engine bays with coils mounted miles away from the normal location (on the bulkhead) but upside down.
I spent a while going through my "collection" of coils and after cleaning up the contacts on the 500 Ohm coil, with a file (wet & dry paper wasn't person enough), it became a 3 Ohm coil. So all the 4 coils, I now own, are withing 0.5 Ohms of each other and they ALL work, including the original Delco coil that brought me to a standstill (but it is cold now - heat test to follow).
Original Coil being tested, with only very slight additional clean of the contacts[frame]Image[/frame]
Next we have the £5 "refurbished" Lucas coil (exterior cleaned up and looking very nice) - working OK[frame]Image[/frame]
Then the 500 Ohm coil that is now approx 3 Ohm working OK - see the fan blades spinning[frame]Image[/frame]
And then the brand new Lucas coil, fitted the other way up[frame]Image[/frame]
Lambrettalad - note the now all black ignition leads. There is a drawback with the black silicon lead in that the insulation tape wrapped round them to write the plug number on, doesn't stick to the silicon!
Back to my repostioned coil - I am very unhappy about this postion with only one bolt holding it on, because it now vibrates very much with the engine running "shaken and not stirred" - can't be doing it any good.
My wiring loom won't allow positioning of the coil on the inner wing without fitting wiring extensions.
Mounting the dubious "new" design coils in the horizontal position is not an option, I think, as the alledged 30% air gap cannot be agitated enough to cover all the internal transformer wiring.
I remember opening up an old failed Nissan Micra coil and the pressurised contents just exploding out (no air gap).
I have not found anything on the tinternet discussing coil orientation - maybe direct questions to all the major retailers are in order?
I feel a new thread coming on .... :D
Have a good evening all,
George.