I was out for a drive this evening in Mr ToAd (MGB bases TA) and had covered 20 miles or so and the ignition packed up. I have had this problem before with a faulty coil but its been fine since the coil was replaced. Changing the condenser gets it going again but condensers only last about 50 miles before they die. Surely I can't have killed another coil? The only obvious problem is a very wobbly top plate in the distributor the one that the condenser screws into.

Any thoughts? All idea welcome!

The car is positive earth, running on a 25D distributor, MGB engine with twin HS4 carbs.

Would electronic ignition we worth considering - if so what sort is best?

Cheers
Jeremy

Hi Jeremy,

Just a long shot is the "wobbly top plate in the distributor" cutting the insulation on the condenser wire? Could this be the problem.

I hope you get "Mr Toad" sorted before the main NG'ing season.

All the Best RobG.

If the wire is chafing, it will be shorting to earth, hence no spark. My TA has an Alden electronic distributor. It was on the car when I purchased it back in September. It ran great for the 200 miles home, even though the camshaft was shot at. As I have returned the engine back to standard, from the Weber carb and 714 camshaft, I returned the 'dissy' to Alden and they re- profiled the electrics and fitted a new vacuum unit. I have yet to run the re-built engine so I do not know whether it works; should do, as there is a spark at the plugs.
The system does not entail any other electronic boxes, just the distributor and your original coil (providing you have not burned it out. The distributor is around £135.
Hope you fix it.
Ron

Thanks verymuch for the helpful comments. I'll investigate the wire as you say Rob it could easilyhave been broken due to the movement in the top plate. Perhaps I can do a temp fix while I investigate the electronic ignition options. The Alden looks to have a good reputation. Running positive earth might cut down the posibilities though. Something to keep me occupied with this coming weekend!

Cheers
Jeremy

Hi Jeremy.
Here is a link to the positive earth section on Alden's web site. I have not read it, but you will probably know what they are talking about.
After fitting the adjusted distributor they supplied me with, my re-built engine started first turn of the key this morning. I had primed the carb, but even with a rough guess at the timing, it fired up. All I need now is a timing light and it is sorted. Getting closer to being back on the road!!

http://www.aldonauto.co.uk/shop/product.asp?strParents=&CAT_ID=0&P_ID=96&strPageHistory=search&numSearchStartRecord=1

Great thanks Ron. I'll have a good read through.

The Aldon distributor seems to get better reviews than some of the others so it seems a sensible route to take.

Sounds like you are making good progress with your TA hope to see it sometine.

Cheers
Jeremy

Hi Jeremy.
Yes, the Alden is simple. Just your normal 'dissy', that contains an igniter where the points used to be. You connect the red wire to positive on the coil, and black to negative (or maybe the other way round in your case), and away you go.
You just have to make sure you give Alden the full spec of your engine,ie carb type, any sort of cam, that kind of thing, and they set the dissy up to the correct spec for you.
Yes the TA is coming along nicely. Another couple of months should see her on the road for a shake down. Just having to design the back half of the exhaust system at the moment. Done the measurements, doing the drawings, then I send them off to GS Exhausts and hope for the best.
Your photos bring back memories of our trip to Scotland just after I had built my TA. I think the story will be in the next copy of ChaNGing Gear.
I am sure we will meet at sometime.
Good luck with the ignition.
Ron

Hi Jeremy - soz to hear that Mt ToAd is misbehaving !!
I am not familiar with +ve earth systems but the only time I have had a coil fail is when Rocket was rewired and an 'auto electrician', would have been better suited to rangling cows, thought it a good idea to omit the ballast resistor - thus overdriving the 6volt coil, frying that and the electronic ignition module.
Are you perhaps fitting a 6volt coil and no resistor ?
On the subject of electronic ignition: Rocket has a Mallory unit which works fine but is US made and parts sre only available from one or two outlets in the UK - if those go out of business then I will then have to make a change.
I would probably opt for Lumenition
They do a conversion for +ve earth - I will email you a link to their Tech bulletin
You will need to get this thoroughly sorted if you are going to do Italy with any worries
regards - Chris

Hi Jeremy,
I have converted my dizzy with the Accu Spark conversion (under £30 )
on my last 2 NG`s & have had 30000 miles trouble free motoring.The kit is easy to fit with an explanatory video available on line. Can highly recomend it.
Good Luck John

Hi Jeremy,
I have converted my dizzy with the Accu Spark conversion (under £30 )
on my last 2 NG`s & have had 30000 miles trouble free motoring.The kit is easy to fit with an explanatory video available on line. Can highly recomend it.
Good Luck John
PS My car is neg earth so should check with Accu Spark that they have a suitable kit.

Thanks every one for your helpful comments, I have got Mr ToAd running again with "old fashioned" ignition whilst I look into the electronic options.

I have invested in some "good quality" condensers from Brown and Gammons in the hope that this solves the problem, and I will also carry more ignition spares in the car in future. There remains some doubt as to the voltage of the ignition coil - I think it is 12v but there are no markings on it - having a ballast resistor coil running at 12v when it should be at 6 or 9 volts could be the issue - it does get rather hot! I have a new spare sports coil ready to fit.

thinking about electronic options - The hall effect triggers don't seem to get terribly good reviews, the optical much better. But there is a price difference of course. I'll let you know what I decide.

Many thanks again
Jeremy

Hi Jeremy,

I to had problems with electronic ign system ie it required the almost '12v' to operate but when the 'B' engine is starting (cranking) the volts dropped down to 10.2v and the unit would function ie no spark. That was from a company called 'BBC' which advertised on Ebay.
The seller didn't have much of a clue although he thought I was the twit, he suggested I take the supply from another 12v source! then I realised he wasn't up to being an electrical person!
In My car now I have a 'hall effect' sensor which can from him and it works fine but the complete electronic distributor (different system) wouldn't work as described above.

Anyway 'Italy'; you may have a buddy, when are you thinking of going.

give me a call 01795 870505 Mick