AC low side too high (100psi)

[gmonkry79]

87 Nissan Sentra AC not cooling!

I started having problems after my high pressure hose blew. I replaced the hose and vacuumed the system...although I’m not sure if I did that right because there were no instructions that came with the vac. I hooked the vac up to an air-compressor then to the low side and let it run for like 10min....Then put 8oz of oil and 1 can of 134a, after that I checked the pressure and it reads in the yellow area which is slightly too high. But when the compressor cycles off the pressure jumps up to 100psi and some times it won't cycle back on till the car is moving. The only time the pressure drops down to normal is when the car is moving or I rev the engine up to higher rpm's. Is it normal for the pressure to flux when U rev the engine to higher rpm's. Is the pressure switch malfunctioning or is it some other issue...SOMEONE PLEASE HELP! IT FREAKING HOT OUT THERE!