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TR2/3/3A TR3 ignition misfire

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M

mapleaf

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I'm trying to find the cause of a misfire on my 60 3A and was wondering if I'm on the right track. I hooked up my timing light to each plug wire and found that the light flashed normally on cylinders 2,3&4, but flashed inconsistently on #1. Is this a good indication that the misfire is probably in the #1 cylinder?? and if so, is there anything else but a faulty spark plug, wire, or distributor cap that could possibly cause it. TIA
 
Those are the most likely reasons. I would exchange the cylinder 1 and 2 plugs and see if the misfire moves with the plug. If so that is the problem. I would than do the same procedure with the wire. And, finally check the distributor cap for carbon tracks or corroded contacts if the previous 2 checks haven't fixed the problem. If all of these have not corrected the problem, than run a compression check.

Phil

Let us know how it goes.
 
Thanks for the tips, Phil
Well, I think I've finally eliminated the misfire by turning the distributor ccw (advance??) until the timing light flashed normally on the #1 and the other plug wires. I haven't had it out for a road test yet, but it sure sound better. I might add that I only tried this after changing the #1 spark plug and wire, the rotor, distributor cap and ht lead, and checking the compression (145-155 lbs), all with no improvement.
I'm still puzzled as to why a misfire caused by the timing being off would only affect the #1 cylinder and not the others. Any ideas?
 
If you turned the distributor CCW, that retards the timing. As to why only one cylinder was affected...I don't really know. Perhaps a worn distributor shaft...by moving the distributor, it gave the points more coil saturation time for that cylinder. You should check the play in the distributor shaft. You might also want to check the timing statically, as that's how the timing on these engines are set.
 
I took the TR for a test run after checking the timing statically and it's running well in spite of some noticeable play in the distributor shaft. Assuming it's a worn bushing I'm wondering whether there would be much difference in cost for just having the bushing replaced compared to a complete distributor rebuild? Anyone checked the costs lately? Thanks
 
Here is a link to Advanced Distributors website and the page where he lists the typical services:

https://www.advanceddistributors.com/services07_2.htm

Here is a link to Moss Motors catalog page showing ignition parts:

https://www.mossmotors.com/Shop/ViewProducts.aspx?PlateIndexID=29171#18

If the wear is only in the shaft bushing, Moss can provide the bushing, but you have to remove and replace it yourself. If there is wear on the main shaft and the upper cam shaft parts may be hard to find, since Moss list them as NA.

I had Jeff at Advanced Distributors rebuild my TR3 distributor a year or so ago and was very pleased with his work and the price was very reasonable.
 
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