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TR4/4A TR4 points turning white????

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TR4

TR4

Jedi Knight
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I tuned up the TR4 and it ran great for about 75 miles and then started sputtering. I pulled the distributor cap and the points had a little white deposit on them probably causing them to stick. I changed the points and the car once again is running great. What would cause this? Anyone know what to check out??? /ubbthreads/images/graemlins/confused.gif /ubbthreads/images/graemlins/cheers.gif
 
Not sure, but sounds like corrosion. Any chance you have some moisture problems?

Mickey
 
I wouldn't think I have a moisture problem. The car never sees water other than a damp sponge. The points that turned white were new ones too.
 
Hmm this is a shot in the dark here, but if they go bad again so quickly I'd have a peak at your voltage. Too much voltage could cause a similar problem to what you describe.
 
I've seen that happen when the condenser goes bad, I would definitely change that if you didn't already do it when you changed the points. /ubbthreads/images/graemlins/canpatriot.GIF /ubbthreads/images/graemlins/canpatriot.GIF
 
In the too much voltage department as above, you didn't happen to put a hot coil on. The Lucas works well but some of the hot ones from the American market don't fair well with the points in our cars. I've seen them melt the plastic that rides on the distributor cam. Wayne
 
While you're looking at that coil you might measure the resistance across the terminals. The correct coil for a TR4 should not require an exernal ballast resistor and should measure about 3 to 4 ohms. If it measures around 1.5 ohms then it is a coil which needs an external ballast resistor... running it without one will work for awhile but will cook the points.
 
Well, this time I ordered a new coil from Moss along with another condensor since the old coil on the car was from NAPA so we shall see if that was the problem. I guess investing in an OHM meter would be advisable. /ubbthreads/images/graemlins/grin.gif
 
[ QUOTE ]
...I ordered a new coil from Moss... I guess investing in an OHM meter would be advisable. /ubbthreads/images/graemlins/grin.gif

[/ QUOTE ]

Yes, a multimeter is a must-have tool. Cheap digitals are inexpensive, durable and accurate enough for what we're usually doing. An analog is needed for couple of checks.

Oh, and check that new coil from Moss to be sure it is the correct type (3-4 ohms, does not require and external resistor). Do not assume they sent you an exact replacement.
 
Well, the coil was at 1.5 ohms on the car and the new coil is at 2.5 from Moss. The car is running great but we shall see for how long. I did have the old coil that came with the car and that read 2.2 so I feel good for the moment. Thanks all for your support. /ubbthreads/images/graemlins/cheers.gif /ubbthreads/images/graemlins/thirsty.gif
 
I think you have the wrong coil.

My personal experience was when I ordered a coil with a push-on HT lead Moss supplied a coil that requires a ballast resistor (p/n 143-220). AFAIK the only stock TR coil Moss offers that does not require an external resistor is the one with a screw-type HT lead (p/n 543-020).

I could have added a big ceramic resistor on there but instead returned it and got a Lucas Sport Coil (p/n 143-200). Better, plus it is a push-on HT that does not require the resistor (measures 3.4 ohms).

The car will indeed 'run great' with the coil you have on there -- but I expect it will again cook the points.
 
It sure is hard to argue with experience. I'll order that Sport Coil that worked for you. I even remember the previous owner telling me he had the car tuned up 4 times and he only drove the car 500 miles in 15 years. At that time, I assumed it was because he never drove the car. Thanks for sharing your experience. /ubbthreads/images/graemlins/thirsty.gif /ubbthreads/images/graemlins/cheers.gif

Phil
 
Well Thank you very much Mr. Hahn. The car now has the correct coil and has been running like new without cooking the points. You topped my specialist who only hit the points with emery cloth so the car ran good for 50 miles but this new coil has had the car out for 250 miles and still perfect. I really appreciate your help. /ubbthreads/images/graemlins/cheers.gif
 
Glad it helped... now for an 'epilogue' (with a moral):

On our club's January Breakfast Run my Lucas Sport Coil died. One minute it was fine, the next it was dead. The coil had 3 years/18K miles on it. Fortunately I had an old spare coil in the boot and a length of nylon rope to lash it to the failed coil. Wasn't even late for breakfast though I did 'win' our POR (Press On Regardless) Trophy:

POR_Trophy.jpg


That same spare coil also brought a TR3 (not mine) back to Silver City from the Gila National Forest last fall. Now it's back in the boot as I got another Lucas Sport.

Moral -- The small size, ease of installation and likelyhood of failure make a spare coil a reasonable thing to have with you.
 
Interesting fact which probably doesn't apply to this situation:

In very high voltage ignition systems, the distributor cap should be vented. There is so much high voltage electricity jumping around, so to speak, that ozone is actually created which can encourage crossfire and misfire.
 
Hey Webb,
That's why an MSD is the best way to improve spark. The points become a trigger for the MSD & carry very low voltage both eliminating under cap arcing & the points last way longer. In case of an MSD failure two wires get switched & your on your way by passing the MSD.
This unit delivers a far superior spark than just a coil upgrade.
 
I have had good luck running a Mallory dual point distributor with a Lucus sport coil for about 15 - 20 years on my TR3. All I have to remember is to check and regap the points every year or two.
 
trboost: Are you using points, magnet switch, or light switch in the distributor? As I understand the dwell is never a problem with the mag or light type switching and when these alternates work you get a more even firing and no points to worry with. And the condenser, temp changes and other variances that may effect the switching are eliminated with the alternates. BTW, do you use the condenser with the MSD? How did you decide to use the points over the other alternates? Which MSD box are you using? Which coil are you using? Sorry for all the questions but your inovation is interesting. Thanks in advance for your answers.
 
I'm very conservitive when it comes to roadside failures. If I don't have a redundancy in place to get me going I generally won't upgrade to the product. I like using the car but try not to carry a spare car with me /ubbthreads/images/graemlins/crazy.gif .
I have never found anything wrong with the Lucas distributor & have nothing against points but I've heard about lots of magnet & electronic component failures with the Crane & Petronix units. I have an electric fan but keep the mechanical. 5 extra HP is not worth a two hour tow.
I use an MSD 6A with a MSD boost timing master & their recomended 8mm wires. Along with that I added an Accel coil & Standard ign "blue streak" points. I use the condensor but am not sure of it's need in the system now. I leave it there to convert to regular ign in case of a failure.
The MSD takes care of the dwel , which really confused me when I first installed it & tried to set the points with a meter. There tech lines & info are excelent. Any one that has increased fuel/air consumption will benifit from this system & it will work with the electronic ign upgrades. As far as I'm concerned it's as close to a fully electronic ign as you can get with out any downside & plenty to gain in performance. As long as your distributor is with in spec it's the way to go.
 
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