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TR6 TR6 died - moving plate earth lead fired

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tdskip

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Yes, I was asking for this based on my earlier post about just driving. But - in my defense - I don't think the part that broke was anyone's spare list!

This is the 1971 TR6 with the new Pertronix and rebuilt distributor.

I was out for a quick run before sunset, and I heard a "pop" and the car immediately died. Suspecting the ignition I pulled the distributor cap and the moving plate earth wire was fried.

I have a spare set of points & condenser, but I don't think that will address the issue.

My idea is to fabricate a new ground wire and hook it up exactly as the wire that burned. Yes/no?

What do you guys think?
 
Well, that's the first logical move. And hopefully nothing in the Pertronix was damaged and it will run again with no problem.

The question is why did it fry? Was it pinched or rubbing the side of the housing?

Here is a Pertronix trouble shooting chart:
 
Hi Paul - I don't know. I installed the rebuilt distributor, hooked the wires up according to the diagram, and set the static timing.

She started right up, I drove her for a 10-15 minutes and then put her away for a week.

When i went to start her this AM it took a lot of cranking, then she caught and was running really well. 5 minutes into the drive POP.
 
I rebuilt the distributor! The only thing that would fry the ground wire is a large surge of current - and the only way that can happen is if there is a short form the HT side through the ground wire. I would suggest replacing the cap and rotor and install the points. With the Pertronix, the gound wire isn't absolutley necessary, but it is a nice safety feature to prevent damage should a major short occur.
This may be the result of a bad rotor, as there has been major discussion on that in the past several weeks/months. I can't recall if I threw in a good rotor for you?
Also be absolutley certain that the disritbutor did not become loose in the clamp! That happens on occasion with new installations.
Please let me know what you find!
Jeff
 
Hi Jeff,

I admire a person that steps up and takes ownership, then immediately looks for a solution. It is a sign of a responsible businessman. And saves unnecessary time.

After you rebuilt my dizzy and I ran it you have my recommendation and this only strengthens that opinion.
 
I'll revert back to points.

You did put a new cap & rotor on, so maybe that was it.

I'll also double check the that the dizzy is tight and then report back.

Thanks guys.
 
Well - the dizzy body wasn't loose, I was able to double check that on the way to Starbucks.

Connectors to the coil looked/feel tight.

Next step is to refit the points, assuming I can remember how to do it. LOL.

Would the rotor really cause a short like that?
 
OK - update as of 9:45 AM.

To remove potential issues I pulled the dizzy and made sure it was seating properly. I reset the static timing, and I've got power to the coil and the static timing is right.

I also fashioned a replacement moving plate earth cable and installed in the exact place the old one was.

And..... nothing.

I'm going back w/ jumpers since the TR6 battery is almost dead from the cranking and will see if I have spark at the #1 plug.

I don't have a replacement rotor or cap, and need to resolve this today since I'll be flat out at work tomorrow and then leave for a 10 day business trip.
 
SUCCESS!

Same rotor, same cap. Weird.

Maybe I didn't install the distributor properly, because it was except for replacing the mounting plate earth ground wire the only other thing I changed was to pull and then reinstall the dizzy body.

I also tightened the leads to the coil, maybe that was it.


Thanks for everyone's help, and to be EXTRA clear I think this was my goof and had nothing to do with Jeff's excellent work.

She still takes forever to crank - like a minute before she fires. Any ideas on that?
 
I hate static timing on these cars. If you have a timing light, set the idle at 800-850 and check the timing with the retard/advance disconnected and the line plugged. Make sure that you are at 12 BTDC and if not move it there.

I'll bet that you're timing is retarded way too far. If it's retarded, as I think it is, the idle will probably go up 200 rpms. Back it down to 850 again and check the timing again. You may have to tweak it a bit to get it at 12. That's why we call it "tuning". If it runs good, and starts quickly you can leave it alone or bump it up to 14 and see how that is. Same steps with the idle as before.
 
tdskip said:
She still takes forever to crank - like a minute before she fires. Any ideas on that?
Click to expand...


A minute! Do you know what your ring gear is starting to look like? I agree that timing is a factor here. Did you set your engine up? cam? etc. If stock or modified, try eliminating your vacuum advance timing and switching over to mechanical advance. I have mine set at 8* @ 1000 rpm idle. Works for me. Just make sure you block off the vacuum ports on the carbs.
 
Hi Bill - engine is completely stock as far as I know. I think the timing is just off, since the only thing that changes was the dizzy rebuild and she always started easily before.

When I redid the static timing on the street (I had help pushing her off the road from a guy in a Sunbeam Tiger!) think I just set it without enough advance.

I'm planning on fixing tonight, so I'll report back.

Thanks!
 
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