Re: 90 ac problems

[Andrew Duane USG/PE <duane@zk3.dec.com>]

Hairy green toads from Mars made nscbarry@mail.msy.bellsouth.net say:

> hey all, I've found a 1990 90, not a q :(, that i think i'm going to buy
> tomorrow. The car is super clean, really tight, with only 54k on the
> clock. The one thing that seems to be wrong with it is that the ac when
> switched on in auto mode blows from the proper vents, dash, but when the
> car begins to drive the air switches to the defrost vents, the floor
> vents or the dash and stays at the location it chooses to blow from.
> Additionally if the ac is set at LO temp, and low fan speed, the air
> flow returns to the dash and remains there. The woman who's selling the
> car told me that her mechanic believes that it is some sort of vacume
> problem. Has any one had a similar problem with the older auto ac unit
> like this?  Could this possibly be the control unit itself? How about
> fixes, the unit does still cool very well though even in the 90+
> heat here in new orleans.

Yes, it's vaccuum. BTDT on Angela's 90Q20V. Under hard throttle,
the airflow would switch from dash vents to defrost vents. I thought
she was nuts when she was describing it to me :-)

A few cleaned/fixed vaccuum lines in back of the AC head, and all
is well again in vent-land.

> Also what should the oil pressure be under normal acceleration, seemed
> to be a bit high at 4-5 bar?

That's just about right. 4-5 at revs, 1.5-2 at idle

> The idle also seems to be a bit rough, not at all unpleasant in fact i
> like the sound of the engine, just not as smooth as my A6. Is this just
> a character of the I5?

Maybe. It could be a slightly dirty ISV.

> Obviously i'm going to have to get a Bible, bently, for this car so what
> is a good source for one, local barns&noble?

Just got mine from Amazon. They give 15% off, and if you click
through the link on Dan's Quattro page, he gets a small kickback.

-- 

Andrew L. Duane (JOT-7)			duane@zk3.dec.com
Compaq Computer Corporation		(603)-884-1294
110 Spit Brook Road
M/S ZKO3-3/U14
Nashua, NH    03062-2698

Only my cat shares my opinions, and she's too psychotic to express it