Auto Air Conditioning & Heater Repair: a/c reduces blowing when accelerating, cherokee 4x4, engine firewall

Question
i have a 1987 jeep cherokee 4x4, 4.0, and lately i have noticed that when i accerelerate the a/c coming from the vents blows very slowly, but when i resume normal speed the a/c goes back to normal of blowing normally. ex. while at light the a/c blows normally, but as i accelerate the a/c reduces blowing until i reach the speed limit, another example on the freeway at 55 mph the a/c blows normally, but if i am passing or climbing a hill the a/c again reduces until i have gone back to normal speed or coming down the hill.  any help would be greatly appreciated, thank you.

Answer
HELLO DANIEL, YOU HAVE A VACCUM LEAK FROM THE MAIN VACCUM LINE THAT COMES FROM THE ENGINE.ON THE RIGHT FRONT AREA OF THE ENGINE FIREWALL IS WHERE THE MAIN VACCUM LINE COMES INTO THE JEEP.CHECK FOR ANY BROKEN OR SPLIT VACCUM TUBING.
WHEN YOU ACCELERATE YOU LOOSE VACCUM AND THATS WHY THE AIR BLOWS OUT FROM DIFFERENT VENTS.FIND THE LEAK AND THAT SHOULD CORRECT YOUR PROBLEM..

GOOD LUCK,DAVIDT