83 T-Bird Starting Problem

Hey all...
Let me just say thanks again about how helpful you all were when I was asking about switching to R134A. My car has been switched to R134A and now
freezes me out, even with the temp here in Arizona at 115...
But, I have a different problem. This problem has been recurring in the summer for a few years now.
I get in my car in the morning to go to work and it starts fine. I get in my car to come home and sometimes it won't start. It sits in a parking garage during the day so the sun isn't beating down on it, if that matters.
I managed to work around this problem by squirting a small bit of starting fluid at it, when it decided not to start, but, as you can imagine, that's quite the pain in the posterior.
Last summer my husband had to replace my timing cover and while he was at it he replaced the crank positioning sensor. The starting problem stopped dead. It didn't do it again last summer.
This summer it's doing it again, but it seems like it might be a different problem. The old problem was that the car would just crank and not catch. Only starting fluid would help it. This year it tries to catch but just can't quite make it. It'll fire up and die right away, and starting fluid doesn't seem to help. The workaround to this is to make sure I have a novel with me and read for 15 minutes or so until the car decides to start.
I had an 84 T-Bird previous to this one that would vapor lock every now and again and the workaround to that was, again, to hang tight for 15 minutes.
Does anyone have any idea what this might be? I sure liked the fact that I spent half the summer last year without having to pop the hood for that particular problem.
We thought it might have to do with the ignition so we replaced everything we could think of to do with that last year before the we replaced the crank positioning sensor and all of sudden the problem was fixed.
Thanks for any help,
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
Add image file

Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.