850 stalls / hesitates

[Guest]

I currently own a 1993 850 GLT with 122,000 miles. The problem I incur is while driving down the freeway at approximately 70 mph, the engine suddenly hesitates / stalls and then recovers quickly. It seems to do it only on very hot days? The TACH does NOT drop off or go to zero, there are no lights that illuminate on the dash board. The fuel pump and pressure regulator were replaced last year along with a new crank sensor and ignition coil. Any input from the board would be greatly appreciated