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TR2/3/3A Does your rotor wiggle

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TR Mike

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I am doing a minor tune up on a 59 TR3a; plugs, points, condenser, etc. I am using the static timing procedure described on the Macy's Garage website. The car ran reasonably well before I started, but now it won't start. I noticed that with the distributer cap off if I try twisting the rotor, there is a considerable amount of wiggle in it. The rotor is not loose on the four sided cam, but the whole cam wiggles with the rotor. Is this normal or should it be tight?
 
It is normal, but it should be spring loaded back to the same position when you let go of it. The wiggle is the mechanical advance mechanism under the point plate.
 
I thought that might be the case since the car ran well before I started. I just never noticed the "wiggle" before and wanted to make sure I hadn't loosened something that was now causing my starting problems. I will start back the beginning of the procedure and try it again today.

Thanks for the response.
 
If you put points on, check to make sure the wire from coil and condenser are in the correct order and have the insulator in the correct position. You may be grounding out the points.
 
Kleykamp said:
If you put points on, check to make sure the wire from coil and condenser are in the correct order and have the insulator in the correct position. You may be grounding out the points.
Click to expand...

That's a good "point". These cars are so old that the hot wire to the points can break or ground as it enters the distributor and makes the tight turn to the point assembly.
 
Yes, getting that little 3-layer cake baked in the wrong order is easy to do and will kill the ignition.

Note that the drawing shows parts #7 and #2 as separate pieces but in some points sets they are a single piece molded with a connector (sort of white nylon or plastic).
 
Thanks for the responses. I started over from the beginning the next day. I am not sure what my actual problem was but I am up and running now.

The procedure for setting the timing on the Macy's Garage website is very well written. It doesn't address this issue though. The "wiggle in my rotor" was enough to cause the points to be either open or closed depending on the initial position of the rotor. I think you could start with the rotor twisted all the way clockwise, or all the way counterclockwise, and get different results. This may be why it worked on my second try and not my first.
 
It sounds like you have an issue with the mechanical advance. As stated earlier, as much as an additional 15 degrees of advancement is available from the mechanical advance. Two springs on two weights under the points plate should return to 0 when you rotate the rotor. One spring is heavy, and probably not intended to have force on it at rest, but the smaller spring should return the advance to 0 when it is not spinning. The speed of rotation causes the weights to move outward, against the force of the springs (and adds advance). The combined effect of these two springs (and weights) create the "timing advance curve" (actually a knee) but they are intended to start at 0.
 
The weights can get gummed up and not move freely - which may be what you are experiencing. When you twist (wiggle) the rotor to its advanced position it should snap back smartly when released. Sounds like yours just stays where you put it. The will mess up timing at idle &/or speed with poor running as a result.

Removing the rotor and the base plate (two small screws) from the distributor will reveal the workings of the springs and weights. A thorough cleaning of that area may be in order.

40698A%20%20Weights_zpsbmxisdfg.jpg


Further disasembly is possible by removing the springs, the cam and the weights - though getting it just as far as shown in the photo may be enough for a light cleaning.
 
OK, that makes sense. You are right, when I twist my rotor it stays where I put it. It does not snap back to an original position. If it did, then the Macy's Garage procedure would have consistent results. I won't have time for a few days to look at it further, but it sounds like I might see some improvement with a good cleaning of my distributer. The funny thing is I am happy with the way it is running now. I drove it to the grocery store tonight and didn't have any problems with the way it ran.
 
When it's running the weights will tend to take up the "wiggle" room. It's only during start or idle that you will get erratic timing readings with a bad spring. The weights will advance timing to take up the slack, while point drag will tend to retard timing. Above idle the force of the weights overpowers the drag of the points, so the timing advances...which is usually good for moderate driving. At idle the drag of the points may equal the force of the weights, so you'll get some bouncing of the timing.
 
Another 'wiggle' is a worn shaft. If you go to Pertronix, that isn't as much of an issue.

Perry
 
I keep thinking that if I mess with it too much I may screw it up enough to make it un drivable. It is supposed to be 97 here in Ohio this weekend. I would rather spend time in the TR instead of the F-150.
Maybe it is best to leave things alone until later in the year.
 
That'll work too! I am sure that many TR's have been running for decades with stuck advance mechanisms. It'll run better if it works right, but will run decently without it.
 
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