Poor starting, looking for ideas, Problem Solved. Another win for the World Board. Options

[Gudhjem]

I've been trying to avoid posting this, since I figure everyone's tired of "my car wont start" posts. But, I've reached the end of my rope, I'm out of ideas, and I need some new ones.

I've got a '73 2.0, stock FI, except for a Crane x700 ignition.

Sometimes it starts right up, but often, about half the time now, it wont. The starter cranks, turns over the engine very quickly, but the engine just wont "catch." It just keeps cranking. It acts as if I forgot the rotor or am out of gas (I didn't and I'm not). Happens warm and cold (though possibly more often warm). I can't think of anything I've done to the car that coudl cause this (no engine tinkering to speak of), and it seems to be getting worse. Today, it did the same thing and after cranking for about 15 seconds, seemed to backfire from inside the case. It blew off the little rubber fitting that sits next to the oil filler cap (the one I'm pointing to in the pic). This happened twice.

The kicker is that once it starts, it runs like a champ. I mean really well - smooth all the way thorugh the range, plenty of power, no smoke out the exhaust, relatively smooth idle at about 800, etc. That forutnatly (or maybe unfortunatly) eliminates most of the reasons why a car wont start. I don't need to worry that my plug wires or injector leads are crossed, or that my plug wires are bad, or my coil is bad, or my Fireball isn't working, or my injectors are not squirting, or that I have no compression, or that I have no fuel pressure, or that my timing is way off, that I have a bad connection or ground somewhere, or that my dizzy is in backward.

Here's what I've tried:
checked timing
checked fuel pressure (set it to 29lbs)
verified spark at the plugs
removed cold start valve wires
replaced spark plugs (0.028")
replaced coil (bosch blue)
replaced spark plug wires
replaced cap and rotor


Seems to me that since it runs so well once started, the MPS and temp sensors or brain could not be the causes. It does look wet when I pear down the throttle body (inside the air distributor thing the throttle body sits on), and although the plugs I pulled were black and a little bit moist, they were not really fouled. So I have spark, I have timing, and I have fuel, I am suspicious that it must be a mixture thing, but don't know where to go with that, and again, it runs so well when it starts.

Any ideas?

--Steve