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MG TD TF 1500 - Distributor earthing early TD?

I'm having a possible ignition issue on TD-4834. Engine has the early style distributor clamp with a ground wire on the cinch bolt. Where does the other end of the wire afix to? I see no possible location except for one of the Dynamo housing studs that holds the end plates in place on the armature housing. Picture would be helpful. I can't seem to find a pic that shows this detail.

Thanks

Bill Chasser
TD-4834
W. A. Chasser

I used one of the bracket bolts as did Dave Here....

http://www.dbraun99.com/mgtd15470/Engine/Install/slides/Distributer%20ground%20wire%20installed.html
L E D LaVerne

Laverne, I believe my ground strap's lug is smaller than the pivot bolt but I'll recheck it. I'll look at Daves pics as you link wouldn't go through.

Thanks

Bill Chasser

TD-4834
W. A. Chasser

My TD is serial #3453 with the early distributor clamp. I have no separate ground wire and I have (knock wood) had no issues with the ignition. The clamp itself would ground from the "pinch" of the distributor through to the retaining bolt to the block.
C.R. Tyrell

CR. First thanks for your comment. I would think so as well but I have several early clamps now that have the web stranded grounding wire on the pinch bolt. There has been recent discussion regarding miss firing distributors above idle and the lack of that ground strap was one source of the issue. Mine has been dangling loose on the clamp so it thought I would add it back in place. Lucas has so many ground wires in their harnesses it gives me a headache. And every one only works on certain issues. So I'm just trying to ensure this isn't the issue.

Bill Chasser
TD-4834
W. A. Chasser


Believe this is an original wire location. Note: the oval hole in the early distributor clamp allows it to float on the bolt that goes into the block and it does not provide the needed positive ground in its original configuration.

Richard Cameron

Thanks Richard.

Bill Chasser
TD-4834
W. A. Chasser

None on my dizzy bill (4139) but cant say it did not come with one. Never had any issues when running either points or Electronic ignition. I do have a ground from the block to the frame.
Bruce TD4139 Cunha

Thanks Bruce. I just got back to Sacramento. Unloaded the car and will thrash on it tomorrow. If I can get a handful of issues done I hope to drive it to the meeting tomorrow eve
W. A. Chasser

Like a lot of us I've been around all kinds of cars all my life and something I've never encountered is, why do you need a separate external ground strap on the distributor when everything is bolted metal to metal? As long as the engine is grounded it makes no sense. There's none on my TF, never has been to my knowledge. Is this a British overkill or what? Could be the makers of ground straps is pushing this as they need more business. LOL! PJ
Paul161

I think the earth strap maybe a leftover from when cars had manual advance/retard. It serves no useful purpose on our engines as the dizzy is solidly fastened to the block.
Ray TF 2884
Ray Lee raybar2(at) tiscalidotcodotuk

As a retired engineer of electrical sciences I fully agree.

There is enough conductiv material for the current.
Bela

The later cotter bolt mount type directly clamp the block/bolt/distributor tightly and would likely ground well. The manual adjust has all kinds of movement and so on. I agree with Ray, those would really need it. The early TD dizzy with the clamp is supported by the clamp, and not tightly held to the block at all, so not a bad idea to have strap on those. That said, dad bought my car in the early 70s and it has never had the ground strap with points or two kinds of electronics and I have never had a problem. George
George Butz

Bill, you may wish to look at the ground strap from the transmission to the frame. You may have a questionable ground there due to corrosion in the braid and end that fixes to both points. It may require replacement or a really good cleaning.

Sometimes the braid looks really good but the actual connection is questionable. I think it would be worth a look.
... CR
C.R. Tyrell

This thread was discussed between 04/07/2016 and 07/07/2016

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