'91 626 Won't start easily or when hot

Hey Folks - I'm hoping someone can point me in the right direction here.

I just got a '91 626 which is in really excellent condition but didn't run. I have one just like it that runs really well, but the body is beat up bad. I was hoping to put the best of both together. The problem with the new one is that it starts when cold, but not easily, and it won't start at all when it's hot. It's the 4 cylinder non-turbo automatic LX model with the power/economy switch, which I've never seen before. It has about 180,000 miles on it. I've replaced plugs, wires, & filters just because that way I know it's done. I've pulled the timing belt cover; the belt is snug, and with the crankshaft pulley lined up to the notch, the top rocker pulley is lined up to the arrow on #1. Not sure if the ignition timing is right, but I got it close as I could statically - I'll have to be able to keep it running to really time it!

If it is cold, you can crank it for a while, and it might catch. If it catches and starts, it will run fine - A little hot, but not bad. But if you shut it off or it stalls, it will not start again.

I've checked, cleaned, and re-seated all electrical connections, and pulled off the manifold throttle body and cleaned it thoroughly.

Don't know what else to do, and the two books I have are no help.

Anybody want to try and point me in the right direction? I'd be really grateful!
Thank you very much! KC