'07 Forenza pressure confusion

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craigecooper
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'07 Forenza pressure confusion

Post by 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
Posts: 9
Joined: Sun Jun 12, 2016 7:45 pm

Re: '07 Forenza pressure confusion

Post by craigecooper »

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

Craig
craigecooper
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Joined: Sun Jun 12, 2016 7:45 pm

Re: '07 Forenza pressure confusion

Post by 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
Posts: 4
Joined: Sun May 29, 2016 10:29 pm

Re: '07 Forenza pressure confusion

Post by REK »

That high pressure is low for that ambient temp. Are you sure it has enough refrigerant in it ?
craigecooper
Posts: 9
Joined: Sun Jun 12, 2016 7:45 pm

Re: '07 Forenza pressure confusion

Post by 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
Posts: 77
Joined: Tue May 24, 2016 5:53 am

Re: '07 Forenza pressure confusion

Post by 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
Posts: 9
Joined: Sun Jun 12, 2016 7:45 pm

Re: '07 Forenza pressure confusion

Post by 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
Posts: 9
Joined: Sun Jun 12, 2016 7:45 pm

Re: '07 Forenza pressure confusion

Post by 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
Posts: 9
Joined: Sun Jun 12, 2016 7:45 pm

Re: '07 Forenza pressure confusion

Post by 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
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