1999 AC job. Rein over nissens, adjustable orfice valve

[jimmy57]

I have installed several VOVs in different vehicles. Maybe a dozen. On one vehicle it worked and is still installed. On many I had to remove and put the standard one in. On 4-5 it is still installed but the system didn't seem to be any colder. The original promise is that the VOV will fix the issue where due to low engine and resulting low compressor pumping rate, the pressure difference in system doesn't encourage good evaporation of refrigerant. I harp on here about NEVER idling engine when you are diagnosing or charging a/c system due to low compressor efficiency and the pressures being out of range for any decisions. Volvo instructions for a/c service is engine speed elevated. But back to the issue here, I don't use them any more because they have inconsistent results.

[abscate]

The 'five river mechanics' here are awesome for combination of experience and willingness to share.

Thanks, jimmy.

[sleddriver]

A TXV would fix all of this.

I can tell when in traffic the condenser gets heat-soaked, even with RECIRC on (which it always is here). The refrigerant is still a vapor at the orfice. Much like a spray can when it gets empty; rather than spraying ingredient in a nice pattern, it just 'spits'.

I'd advise against "variable" as well....

[wizechatmgr]

And the no variables have it!

[June]

Is it cruel to make my 87 year old Mom the Guinea Pig on this, June??

yes! she might put you in time out for screwing up her ac June

[abscate]

Wrap up...

We used the Nissens evaporator and the standard Volvo orfice valve, aftermarket.

Rein for the drier.

I got the best AC delta I’ve ever done, 43F at 83 F ambient.