Ignition timing - odd behavior

So you've hit the right question. Following the earlier suggestion I did the 'thumb' test to find compression stroke on #1, and I am WELL away from 0 degrees. As best I could estimate, I am 1/3 of a rotation from 0 degree mark. In other words, if my 0 degree mark is at 12 o'clock, the compression stroke would have been at 4 o'clock on the harmonic balancer. How does this happen, what does it mean, and what can I do about it? I suspect it means the guy who re-built my engine did something wrong! Feeling nervous here...

I'll admit this was the first time I tried to find compression stroke with thumb over spark plug #1 opening. It was a fairly subtle amount of pressure, but I repeated it a few times to be confident that I was doing it correctly....

ok, my firing order is: 18456273 (per plate mounted on engine).

right, in what I called Position A: rotor is pointing to distr cap terminal for spark plug #1. I have it pointing directly at #1 with engine at TDC (I still need to do the check to make sure I'm not off by 180 degrees). Engine refuses to start in this position, and only starts if I rotate it CW to be about 1/2 way to the next spark plug terminal. But at that position (my Position B) the engine doesn't run correctly (idle speed, timing, etc.).

Ok, didn't realize that - thanks!

So, if I do have the true TDC and spark plug #1.... then I'm still lost in terms of what I'm seeing when starting/running this engine....   Anyone else ever run into this situation?

OR the thumb over the #1 plug hole method ... which ever works best for you

Gary - Your timing light issue may be because of spark plug wire position.

TDC mark on harmonic balancer comes around twice, so maybe it was not on correct part of cycle.

Also, are you calling #1 as the front starboard plug?

Sorry if this info is too basic.

Hope you get it figured out soon!

I checked the movement of the mechanical advance. They are not frozen/bound, and I did lubricate lightly. But I did noticed that the two springs are not a matching pair. One on right is light (almost as light weight as you would find in an old pen) and is engaged/tight. The one on the left is much heavier, and quite loose. Not sure it this is as it should be, or if it is a potential issue.... Attaching picture:

Gary,
Since the rotor does move, it indicates the advance isn't locked up but, you don't know if the advance moves all the way. To check and lubricate, the point plate needs to come out since the mechanical is below it.

[a] forgot to mention... I'm in northern VA (outside of Washington DC).
"mechanical advance free to move in the distributor": I don't know. I'll need to check that, but I'll first need to find the mechanical advance. I think I found you-tube video that will help...

Gary

Gary,
Is the mechanical advance free to move in the distributor? They will rust up.

I been working through a series of issues with my 1978 Mustang 17 (Ford 302), and had some postings last year. At this time, I'm working to get engine running after having it re-built (2017 winter) and re-assembled (within the last few weeks). I'm a novice, so I'm doing the best I can with information that I can find.

I believe that the engine and most components are in reasonably good shape. Engine will run, but it is behaving strangely. Recently, I have done the following:
[a] attempted to get distributor in proper alignment by having engine at TDC with rotor pointing at spark plug #1 (and I have checked/double-checked firing order, spark plug wiring). I'll call this position A. At position A, I can't get the engine to start, not even close!

The only way I can get engine to start is to rotate distributor clock-wise about 1/2 the distance to the next spark plug post in the distributor cap. I'll call this position B. At position B, the engine will start consistently, but it idles fast as ~1600 RPM (carb idle adjustment will not reduce idle speed). And, when I try to get timing reading I find that it is off the scale completely.

So, then I adjust distributor in counter clockwise rotation and when I get back to position A I find that: (a) I can get idle around 1000 RPM, and (b) I can get a timing reading, (c) and I can fine-tune positioning to get a good reading at 12 degrees. In other words, everything seems fine (as best I can tell) at Position A. But, engine WILL NOT start at this position.

Does this indicate some issue that I need to fix?   I'm thinking it is something obvious to folks who know engines...

I am looking for a local mechanic that can set my timing as I expect an experienced mechanic will understand what I happening (I don't).