A/C not producing sufficient cold air

[mrzzzr1]

Have replaced the Electronic HVAC Controller with one my mechanic found on the west coast. GM original not available any longer. (Original controller was erratic a/c delayed for a period and also cut in and out whenever it felt like).
Have done 2-3 rechages the first two with dye and no leak detected although the feon was down ~.2 lbs. after a couple weeks.
Converted the old R-12 with new R-134a to reduce freon rechage cost.

Mechanic says he has done everything he can. Says the only thing left is there may be a pin hole leak in the evaporator core and he can't, or doesn't want, to fix it.

Have run the a/c for a couple months since with not much change. When it is hot I max out the temp at 60 and the fan on high and it barely keeps up.

A/C only seems to run on "AUTO" setting (is this they way it is supposed to work). When I run the outside air though the system (upr and lwr vents) without a/c it still seems to produce a/c sometimes (another bad HVAC controller).

Any ideas or suggestions are appreciated. :confused:
I think I have spent way too much time and money chasing this one.

[-=Jeff=-]

what is the volume of air out the vents like? the Evap gets pretty gummed up so the amount of air is reduced as well..

As for the AC Controller I have one from a 90, it was verified good in another Z owners car.. if you need it.

Sounds like a A/C programmer issue though

[Jeffvette]

You've got two components which people seem to confuse:

HVAC controller which is the dash unit
HVAC programmer which is just above the gas pedal

People call these the same thing sometimes. When you are not getting dash air control, it is usually the programmer and or the vent door assembly.

[GOLDCYLON]

AC will only run in AUTO unless you lower the fan speed from 10 Highest speed to a lower speed . You will notice then the green light above the auto will turn off but the AC still runs at the operators directed speed. I had a problem simular to this the AC would turn on when it wanted etc etc. Volume of air was great sometimes not so great other times. I ended up replacing the blower motor. A $40 fix and solved the intermitant problem. A fully functioning blower is critical and will cause suitcase/vent controller issues. Other than that a AC programmer above the footwell or a plugged evap as already stated. I would suggest the $40 fix first. The programmer is a bear to find. GC

[-=Jeff=-]

The programmer is a bear to find. GC

Nah finding is easy.. getting under there to R&R that takes some work :D

[GOLDCYLON]

Nah finding is easy.. getting under there to R&R that takes some work :D

Well thats true Jeff but I was refering to how hard it was to get the replacement part. R&R under there is a little more than a bear its a Bi--h :mad: :jawdrop:

Unless your name is Jeffvette he lives for tight places.... LOL
And $1s $5 and $10 and dancing is involved ;)

[-=Jeff=-]

Well thats true Jeff but I was refering to how hard it was to get the replacement part. R&R under there is a little more than a bear its a Bi--h :mad: :jawdrop:

yep, we are both ont he same page.. :thumbsup:

[mrzzzr1]

Volume of air seems good and the blower seems to be doing its job. The temp of the air is not real cold though.

[GOLDCYLON]

Volume of air seems good and the blower seems to be doing its job. The temp of the air is not real cold though.

Ok then move onto the contoller

[Aurora40]

You haven't actually said if the compressor cycles on?

[mrzzzr1]

The compressor cycles on and off. Some cold air is produced but not an adequate amount to make it really cold. I can run the air set a 60 deg and the fan on high constantly and the interior barley cools off.

[mrzzzr1]

what is the volume of air out the vents like? the Evap gets pretty gummed up so the amount of air is reduced as well..



Jeff, how does one go about checking and cleaning the Evaporator?

[gbrtng]

If the compressor cycles, the system is low on freon. A properly charged system runs the compressor continuously.

[-=Jeff=-]

Jeff, how does one go about checking and cleaning the Evaporator?


Try these:

http://vettextc.jiminees.com/jeff/Evaporator/

[GOLDCYLON]

Yeah Jeff I didnt have the heart to tell him he was going to have to pull the suitcase. Great link BTW.

[-=Jeff=-]

Yeah Jeff I didnt have the heart to tell him he was going to have to pull the suitcase. Great link BTW.

YEah that is info i collected over the years..