AC issue and cant find similar issue on here

[Big Ol' Blue]

I have found some of the same issues on here and have tried several fixes, for example i have changed low pressure switch and fix the air gap . Now ill explain as best i can .... I have cold air at idle but when i accelerate air starts to blow warm then when i let off the throttle i hear a bump and it blows cold again (as long as im below 50mph - if above 50mph when i let off the throttle you hear the bump but still blows warm until 50mph or below then goes cold) Now i have found when i start the truck i can idle up to see if the compressor kicks off and if it does i can shut the truck off and start it right back and ill have COLD AC WITH NO PROBLEMS , (no bumps,no warm air) !! "Its crazy" But i know somebody on this forum knows ALOT more than i can seem to figure out . Thanks in advance for any info
OH yeah its a 2004 F350 6.0