2003 Vue AC problem

[jim43bob]

AC clutch cycles quickly(less than a second) maybe every 10 seconds.All lines,receiver,TX valve etc. leading to and from compressor are clear(Disconnected and blew nitrogen through).If I jump out the compressor it climbs to a high head (up to 350lb)and high back of 40lb. and the engine will stall.Trying to figure whats wrong and wonder how sytem is controlled?There appears to be a "Pressure Sensor and Pressure Sensor Valve mounted to the compressor on the manifold holding the liquid and suction line.Could this be the problem?(I don't know what it controls!!)
I'm not even sure what gas was in system when I bought it used, person Ibought it from said air had worked but was probably low on gas(Heard that enough times)
Any help appreciated

Jim

[djb383]

AC clutch cycles quickly(less than a second) maybe every 10 seconds.All lines,receiver,TX valve etc. leading to and from compressor are clear(Disconnected and blew nitrogen through).If I jump out the compressor it climbs to a high head (up to 350lb)and high back of 40lb. and the engine will stall.Trying to figure whats wrong and wonder how sytem is controlled?There appears to be a "Pressure Sensor and Pressure Sensor Valve mounted to the compressor on the manifold holding the liquid and suction line.Could this be the problem?(I don't know what it controls!!)
I'm not even sure what gas was in system when I bought it used, person Ibought it from said air had worked but was probably low on gas(Heard that enough times)
Any help appreciated

Jim

Sounds like a job for a good hvac mechanic. R134A freon is what should be in the system.

[Matt42]

After you blew the nitrogen through, did you evacuate and recharge? If so, how much R-134A did you install? The symptoms resemble a refrigerant overcharge. R-134A systems are very sensitive to overcharge, and seem to work best with a slight undercharge. The best thing to do is evacuate and install the specific weight.

For what it's worth, it hit 120F here yesterday. Cold front coming through reduced that to 117 today.

[fdryer]

AC clutch cycles quickly(less than a second) maybe every 10 seconds.All lines,receiver,TX valve etc. leading to and from compressor are clear(Disconnected and blew nitrogen through).If I jump out the compressor it climbs to a high head (up to 350lb)and high back of 40lb. and the engine will stall.Trying to figure whats wrong and wonder how sytem is controlled?There appears to be a "Pressure Sensor and Pressure Sensor Valve mounted to the compressor on the manifold holding the liquid and suction line.Could this be the problem?(I don't know what it controls!!)
I'm not even sure what gas was in system when I bought it used, person Ibought it from said air had worked but was probably low on gas(Heard that enough times)
Any help appreciated

Jim

If you aren't familiar at all with vehicle air conditioning you would be undertaking a very difficult repair (judging from your post). Try reading A/C Basics in the Miscellaneous Tech section of this site for some information then if you're a glutton for punishment go to http://ackits.com for education and knowledge. Its a friendly site just like here but for vehicle a/c only and there are professional experts to answer the most difficult questions. There aren't any slouches here but fewer a/c experts while the rest of us are DIY'ers. Not to be critical but you seem to be behind the 8-ball and without knowledge of a/c fundamentals you may wind up with more headaches instead of turning to your local a/c repair shop.

BTW the pressure sensor mounted on the compressor is the high pressure safety valve; it releases refrigerant when pressures exceed approximately 450 psi to prevent damage to the compressor and the rest of the a/c system. This valve under normal operation never operates unless an a/c system was compromised by overcharging with refrigerant or a blockage in the system allowed dangerous pressures to build up exceeding the normal pressures (no higher than say 300 psi). The other sensor is the hi/lo pressure sensor mounted on the return line and cuts off power to the clutch coil in the event of too low or too high refrigerant pressure (approx. 20psi low, 190 psi high). The refrigerant used since about '92 is R134a and once an a/c system is opened, as you have done, you must use all the refrigeration equipment to return it back to a sealed system again. This involves the a/c manifold gauges, vacuum pump, R134a, can taps, adapters, and various miscellaneous items. In other words, time and $$$.