91 Honda Civic Sedan Air Conditioner

[tomjeff]

Need some help on get the head pressure down on my 91 Civic. I will idle on about 175 and put out 44 degree (F) temp out of the vents.

When the RPMs get above 1500 the head pressure starts to climb. It will go as high as 400 PSI. Which is way to high.

I have replaced the following with NEW parts not used:
compress, expansion valve, condensor, dryer, evap core, and all the rubber lines. Can the inline pressure valve be causing this. Never seen anything like this on any car.

Bye the way both of the fans are running and will hold a work rag to the grill when they are running. So I dont think air movement is the problem.

I can take a water hose and run cool water over the condensor and that will drive down the head pressure.

Do HONDA's run high head pressure? I am use to GM and Ford which only get to a bout 225.

Help

[tomjeff]

Well just to let you know I got the AC working.

After talking with a lot of AC people at HONDA, they ask me if I knew there was a problem with HONDAs with REAL expansion valves having problems with R134. It seems the PAG46 oil and the 134 are a little thicker thank the mineral oil and 12 which comes in the car from the factory. It alters the what he expansion valve opens and closes which creates higher pressure. They were right.

Two of the mechanics suggested I pull the 134 our and flush the system and replace the dryer. Then filled the system with the old 12 or the newer FREEZE 12.

Well I did all that and now the headpressure is around 170 at idle and less than 200 when it at 2000 rpms.

so here it is for what it worth.