madsteez

Im having a bit of a tricky situation. My ac compressor cycles off,and then back on when ever I give it the slightest bit of throttle.

For instance I can sit over the engine bay,with the ac on while the car idles at 850rpm,the second I rev the engine (1500-2000rpm) the compressor cycles off and then back on.

The low pressure is at 32lbs while the high is at 190lbs. The ac works fine and blows cold air however seeing how the compressor is stubborn it causes for a relatively un-smooth trafficking as the engine has a constant load being taken on/off when ever I go to accelerate.


Any input or idea how to trouble shoot this situation is greatly appreciated.


The car is a stock 99 civic ex.

Fabrik8

AC clutch problem? I'm going to throw that out there but I'll willingly admit to not knowing shit about AC systems.

SortaFlush

Are you 100% positive Jared that the A/c is charged correctly?

You didn't use that stop leak bullshit either from Advance right?

Grease Monkey

is it possible that the system could be under/over charged. The a/c system has generally a high pressure shut off and a low pressure shut off switch to disable the compressor when either of those situations occur. Most likely, when the engine is revved the pressure increases too high and the shut off switch disables the clutch.

I Love (.)(.)

a lot of times when you have a compressor that is cycleing strange it is a incorrect pressure in the freon, meaning it is not charged correctly, or the lines can be clogged. ive battled with many ac problems and gone around in circles with improper pressure in either high side or low side, and had compressors cyleing on and off, or only at certain times and such, and had it be either a clutch problem, as stated by fabrik8, or it be a clogged line. reciever dryers tend to get clogged up also and fuck up the pressure. im not very good with ac systems and never cared to be, but thats my 2 cents

madsteez

Damn you always have the answers though!
I have a manifold and gauges,and it has no leaks.
See not whats what I was thinking considering when I rev the engine,the pressures increase and that is when the compressor cycles off,one the pressures start to drop the compressor cycles back on. The pressures it cuts off at are 40 low side and 150 high side. Everytime I rev it and the gauges hit those pressures the compressor cycles off. I looked around and I can not find a high pressure switch,I do however have a pressure switch on the condenser,im assuming its the low pressure switch for when I unplug it the compressor instantly shuts off.

Well the clutch engages properly and stays engaged through out the entire time the ac is in use,it just likes to shut off when the pressures raise,as stated above.

I Love (.)(.)

well the compressor shouldnt stay on the entire time the ac is on, it will cycle on and off, but irregular cycling is bad, like on and off and on and off within say 1 minute.

madsteez

now it doesnt cycle on/off continuously,if its at idle it does perfectly fine. But as far as I can tell when ever a load is put on it it cycles on/off.


Also,it blows cold when its warm outside,but if its hot outside say 90+ the ac doesnt cool you off to well.

Fabrik8

That would make sense given the problem you're having... The system has to cool hot ambient outside air, and use hot ambient outside air to reject the heat from the compression cycle. So if you have a system that has problems, it won't cool very well even if it is fully charged, etc.

That's all completely obvious I know. I'm just thinking out loud.

I would say in this case that it might be worthwhile to look for an AC specialist, or look really long and hard at the factory manual.

madsteez

jerk you confused me there for a minute hah. I though you were trying to say that I have hot air trapped in my ac lines.