Hmm, yeah mine goes from about 500 rpm to 700 when switched off. But I dont have any upgrades to the fuel system yet so maybe being stock has something to do with it?

 

IDK I had a mechanic tell me that the 134 doesnt work as well in the 12 systems because it is harder to pump. I dont really know much about A/C but thats what the he told me and thats why it doesnt cool as well in a system designed for 12. If he's right and it is harder to move, that would explain decreased idle it seems like

 

i dont see the slightest drop on mine when ac is kicked on. but having an electric fan might be the cause since i dont have the lag of a fan as well and i have 134

 

If u turn your fuel screw 1 or 2 turns that will ldle it up some and give u some more power!

 

Lol, well that is what I meant in my previous post, perhaps its cuz mine is prtty well bone stock that it is a dog and cant even handle turning on the air for it to pull down me power...

 

Mudbug I was wondering why you'd want to change your idle as when winter comes rolling through again you won't be running your AC. Then your engine will idle at 800 - 900 instead of 700 or 750, (whatever it is, I don't have a tach.) Then you'll be messing with your idle screw twice a year to reset it. I think sweetv8s10 has the best idea, adjust your idle with your fuel screw!
I went from R-12 to R-134a and did notice a small variance in the amount the rpm dropped. Maybe 25 rpm as suggested, but I can't be sure. My rpm didn't drop when I was running the R-12, so maybe there's something in that.

 

Good point. Well I probably wont mess with it since it doesnt die. Just vibrates the truck more it seems. Maybe thats comeing from the straight pipe exhaust or something else. I thought perhaps it was from the low idle.

 

granted, i don't know much about A/C either and that makes sense if you're running R-134a in an R-12 system. but, if an R-12 system has been retrofitted to run R-134a, it's not longer an R-12 system, isn't it? that's my opinion of it anyway...

 

Its still and R12 system unless you went thru and tore everything out and replaced it. I cant remember what all he said was different about them but some of the major components are designed differently which is why the 134 in a 12 system never works as good as it used too

 

That would explain why mine isn't as cold anymore. Could be worse though, I could have no AC.