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Tips
Tips

TR6 No spark 1972 TR6

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If you are not getting a spark from the big coil wire when you spin the engine with the starter then the test indicates that the problem is within the distributor....
The culprit is preventing the points from grounding when closed or breaking cleanly from ground when they open
It's that action that energizes the coil....utilizing the 12 volts the coil is fed by your white/yellow wire to generate 20 to 40 thousand volts to make a spark
 
Ah, I see now. I was backwards in my thinking. Will go back to the distributor to check things. Thanks!
 
Check the order of things as well as their condition:
TR6 ignition points 001.JPG
 
That test light is showing that you have 9 volts ---It is not showing you if your coil needs 9 volts or 12 volts to make a spark . ---run a test lead directly from the positive teminal on the battery to the positive terminal on the coil . This will guarantee that you have 12 volts at the coil . ---If you get spark with this set up then you need to bypas the resistor in the wiring harness to use that coil
 
That's a great thought Windsor. I'll give that a shot. What's really weird is that in 40 years, it's never had an issue like this and no wiring has been changed...just the points.
 
I'm not saying don't try that but the 72 cars did not have a ballasted ignition... If you want to see how many volts are actually feeding the coil, here's how:
Leave the w/y wire connected to the + of the coil, but ground the negative terminal of the coil using a jumper to a known GOOD grounding spot.
Then with the IGNITION key in the ON/RUN position use the probes on the volt meter to read the voltage between the positive and negative terminals of the coil.
 
tr6web said:
That's a great thought Windsor. I'll give that a shot. What's really weird is that in 40 years, it's never had an issue like this and no wiring has been changed...just the points.
Click to expand...
Sounds like you should take poolboy's advice and carefully check the sequence of the components of the points assembly (see the diagram poolboy posted).
 
Thanks Gilder. I checked the points, rechecked, stacked them again, tried again, checked and rechecked. And then I did it again for good measure.
 
How are you setting the points strictly by feeler gauge or by using a dwell meter as well? By feeler gauge we are talking a point gap of .015"±.001". That is a tight tolerance band and why my contention is that a dwell meter should be used since it is easier to get more accurate settings. Since these are six cylinder cars, the total amount of distributor rotation during the period for one cylinder to fire would be 360°/6 for the number of cylinders or 60°, that number is fixed. The dwell angle specification on these cars is 35°±3°, this is the number of degrees in distributor rotation that the points are closed during the period for one cylinder to fire. The open period for the points would correspondingly be 25°±3° of distributor rotation during the period for one cylinder to fire which gets us to our 60° of distributor rotation for each cylinder's firing period.

Since triggering the high tension side of the ignition is a function the points opening and closing and the relative amount of time the points are open or closed, if the dwell angle is too low, the voltage in the high tension side of the ignition system will be decreased, sometimes to the point of not being capable of supplying enough voltage to spark.

I am also going to suggest that you go back to post #5 and #12. You really need to check this using a multimeter as Sarastro suggested and not just a test light. A simple multimeter will not break the bank and once you start using one, it will become an indispensable tool for working all manner of things electrical. All a test light will do is show that there is enough voltage to light it up. It will not tell the voltage in the circuit nor will it tell you the resistance along a circuit in a continuity check. With the multimeter, go through the checks that Sarastro laid out earlier.
 
I did a little digging and determined that you can probably kill two birds with one stone as it were, but was past the edit time limit so a new post was required. I have some analog simple dwell meters as well as what they called "engine analyzers" in the analog days that can do more stuff. But now that things are going all digital on us there are some pretty flexible multimeters out there and for low prices as well. Here's a multimeter that also has dwell function and tachometer features for automotive use from Harbor Freight:

Harbor Freight Tools – Quality Tools at Discount Prices Since 1977

Harbor Freight buys their top quality tools from the same factories that supply our competitors. We cut out the middleman and pass the savings to you!
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It isn't clear to me that you checked definitively to see if the points are opening and closing. If they are, you should at least get a spark. Dwell shouldn't matter for that. Use an ohmmeter to see if they are opening and closing as you crank the engine over. If they are opening and closing, and still no spark at the coil, it pretty much has to be the coil. With an ohmmeter, you can check the coil's low and high voltage windings to see if they are open- or short-circuited.

A bad lead from the distributor to the coil is possible, too, but you should be able to check that visually.
 
It's alive!!!!! After all of your kind posts, I went out to the garage tonight, took out the distributor, removed the points, and checked out the ground wire. I carefully reassembled the points, made sure the screw was tightened well, put the distributor back in the car, and it started right up. Not sure if it is the ground or the points assembly, but it's running! Now I just have to dial in the timing. Might need some help on that too! lol

Thanks everyone... your help is more than appreciated.
 
As I’ve learned lately, just because it’s “new” doesn’t mean it works…OR that it has well-written installation instructions in beautifully crafted King’s English.
Trouble-shoot it anyway.
 
pdplot said:
Do they still sell those pre-assembled points? That plastic sleeve is already in the correct position.
Click to expand...
Well sort of already in the correct position. It is in place but you still need to remove that top nut and the top part of the sleeve so you can put the wires from the condenser and low tension lead next to the spring, then put the sleeve and nut back in place. If you just remove the nut then put the condenser and low tension leads on without removing the sleeve to get those wires to get them in contact with the spring and install the nut, you get no spark as there is no continuity on the low tnsion side of the ignition system.

The only way I can think of to where that top part of the sleeve was properly located for no fuss installation would be if the points, condenser, and that low tension lead with insulating block came together all ready assembled. I don't know that Lucas has ever done that. The closest I can think of that they came to that was, if we back ~50 years, was with the 60041004 points and condenser set which has long since been superseded to DTB150 points and condenser set.
 
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