My 95 V6 mystique is having a similar problem. Car runs great when cold, however when it is very hot outside and car gets good and warmed up if I park for a while and engine gets heat soaked it SOMETIMES will barely run. It acts like it's not getting any fuel and idles about 200 rpm.
When I try and put into gear and pull away nothing happens. I go back to neutral and even then have trouble revving up.
Usually it does finally start working and I can drive away and all is fine.
Yesterday it was really hot and it would not clear up,
i barely nursed home the last 20 miles, every stop sign and light was was a major challenge. I had to keep it in the lowest possible gear and keep rolling, hills were murder and I barely made it up my driveway.
This morning it was back to running fine????
Any ideas would be appreciated.

Thanks, Ed.