'07 Forenza pressure confusion

[craigecooper]

I've got most of the tools and with this forums help, have successfully repaired my '97 Grand Am A/C. Thank you very much.
I also have a 2007 Forenza ( I know, but it still runs and was cheap when new ) that has me baffled with diagnosis.
Low 50 / High 140 / outlet air 70 degrees / ambient air 90 degrees / compressor spinning without cycling
Suzuki's never had the best A/C systems but this one used to be better than 70 degrees.
Can anyone offer a suggestion on where to start ? the pressure readings have me baffled.

thanks,
Craig

[craigecooper]

Is it possible the control valve is stuck / partially stuck ? Browsing Alldata and grasping at straws.

Craig

[craigecooper]

Clarification::::
pressure readings were at idle
and it appears to be a GM V5 compressor
70 degree vent temp was best possible at speed / it will climb quickly to 80 when stopped

Craig

[REK]

That high pressure is low for that ambient temp. Are you sure it has enough refrigerant in it ?

[craigecooper]

not certain of the 134a charge or pressure readings. I was hesitant to add any because of the higher than normal low pressure. I may try it again at 1500 rpm and see what the readings are. Is the control valve basically going into bypass at idle? .. so the pressure readings at idle are worthless ?

Craig

[mk378]

Charge by weight first. It is very hard to diagnose a variable compressor system without first ruling out the possibility of over or under charge. The pressures don't respond to the charge amount the same as a conventional system would.

And always test at 1500 rpm. A lot of systems barely work at idle in the first place.

[craigecooper]

if the Forenza V5 ends up needing a control valve, how much pag oil would need to be replaced with a vac and recharge ?

thanks,
Craig

[craigecooper]

added 2lbs of 134a at 1500 rpm
new pressure readings ::: low 55 / high 195
vent temp still a dismal 70 degrees at 80 ambient

not sure what else to try other than a new control valve.
if i have to pull it down to weigh it going back in, I'll definitely change out the valve.

Craig

[craigecooper]

Currently starting the process of replacing the control valve by pulling a vacuum and the 22" vacuum is only showing up on the high side of the gauge. Does that make sense? Thought I would see what a vacuum looked like before replacing the valve. Never had to deal with this variable compressor / control valve scenario so not certain what to expect.

thanks,
Craig