variable orifice problems?

[89VORTEC]

switched my a/c over to 134a a while back, did the lazy-mans swap, vac-down and fill with 134, no oil change or nothing. worked pretty nice, 40* max a/c driving down the road. worked good except sitting at lights, drive thrus, and stuff, compressor would start cycling, and would start climbing up to near 70*

So i decided to spend some more time this time around, flushed all the lines, drained compressor, replaced accumulator, replaced o-rings, fill with new pag 100, etc... But this time i installed a carquest variable orifice tube, hoping to increase low rpm cooling capablitly. HA ... worse .... compressor cycles more now, i can only get about 1.5 lbs in there before i have high side reading of near 400 psi. Low side stays around 40 or so, but these high side readings worry me. It wad around 85-90 *F or so in the shop today, so i would expect higher than normal high side ... but 400?

I have a u/v dye in there so i'll keep my eye out for leaks, but i wont even be using the a/c because it sucks now ... gonna go back to a fixed orifice .... why do they say the variable helps?

[T Man]

400 is more than twice the pressure you want to see in our systems. Take the variable oriface out, put the reg. oraface tube back in, pull it down to 30"hg for an hour. Should compeltly remove all moisture from the system, and then fill with 2.14lb or whatever our trucks take

[Everfalling]

be sure your fan is spinning at proper speed also...most of the time when I see really high pressures like that it's cuz the compressor isn't cooling down enought to release the freon back into the low side...I've had 3 cars just in the last 2 months that all that was needed was the fan replaced and then the pressure was fine as was the freezin azz ac...lol not always the cause but something to look out for

[89VORTEC]

Cool thanks guys, i'll do that next week sometime (this week is my paid vaca!), and the pickup blows 40* on hot days, so i'll just drive that for a while.

My question is, why do ppl say the variable orifice is better for our trucks?

And another question, how come my pickup blows so damn cold when all i did was a lazy-mans retrofit, vac, and fill on it?