After looking more into your first post.

I would have to lay my odds on your torque converter clutch controler not releaseing the converter properly or a plugged up filter.

It seems that your issue is only at slow speeds or stops. Very discriptive of a lock up converter not releasing like it should and locking up. Or very poor fluid flow.

 

My 89 K5 was doing the same thing. I got some of the heavy duty carb/injector spray fron Advance Auto and sprayed it while it was running. I would spray until it almost died and then would stop to let it catch back up. I used the whole can on it and the problem stopped. It had also been idling a little high and the spray fixed that too. I think maybe a port or something may have been clogged in the throttle body.

 

Does the Torque converter issue make sense when it only does it when it is warm? You think it would do it cold also if it was the torque converter...

 

That is the sad thing about trany issues, might show no signs then bam its gone, or it will do odd things like bog your engine cold or hot or just when its warm.

Again, check Fuel PSI
Vac lines
TB
Trany fluid color (makes a big difference when you know the color of this stuff)
And check your Trany repair manual to see if you have a lock up or non lock up converter

I have seen these lock up converters act up only durring certin temps. Has to deal with all the sensors and controlers that deal with it.

 

Just to add one more idea to your list of possibilitys, you might want to check and replace the throttle body base gasket. They have been known to break and leak, causing afast idle and hesitation on accelleration. the gaskets only a couple of bucks and it shouldn't take more than 1/2 an hour to replace it.

 

Well....While driving home Wednesday, the car just totally died...The fuel pump went out...I changed the fuel pump last night and it ran great. Lots more power...However, today at lunch, when it warmed up, it cut out 3 times...I just cannot figure this out. My mechanis is stumped as well. I looked at the Trans fluid and it looked perfect...The mechanic says there is no way that it is the torque converter....Any Ideas? Help?!

 

Kewl not trany, that can get expensive.

When you did the fuel pump did you check the ground? Sometimes just a bad ground can cause all sorts of issues.
Also check your injector plugs, had one that would not start due to a bad plug (pigtail). Pulled them one at a time til she fired up.
Replaced that pigtail/plug and it ran like new.

Just a few thoughts