heater vents not working properly! rough idle after warms up. on 1993 Buick Century

Heater only blows air out the ac vents, when I put lever in the defrost slot, I hear the ac pump kicking in. is there some kind of actuator switch not working? I just bought this car, and I replaced both head gaskets and did a valve job as well, it ran before I did this but since it had a blown head gasket I did not let it warm up enough to know if the idle problem was there prior to tearing into it. when I first start the car, it runs as it should,(rpm's high until gets warmed some) then after it warms up some the idle returns to normal but it wants to die and sounds really rough. Any help would be appreciated.

by in Roseburg, OR on November 07, 2012
2 answers 2 comments
ANSWER by on November 07, 2012
COMMENT by on November 12, 2012
That's what it sounds to me like also, still looking but there are not very many hoses to check. Thanks!
ANSWER by on November 08, 2012
I would take it back to the shop that did the heads
COMMENT by on November 12, 2012
Yeah that would be me. As I stated earlier, I just bought it and re-did the heads. It ran but lousy, due to blown head gasket. I did not let it warm up enough to know if it had a rough idle before I bought it. I am just guessing the problem already existed. I will keep looking for vacuum leak for now. Thanks. UPDATE: No vacuum leak found, replaced IAC valve and it tries to idle, I had to use the manual idle adjust to keep it running. Went for a drive and there is a dead spot in the throttle, it will not maintain steady, even throttle, I have to continually keep the throttle moving. WOT works fine, until I try to hold throttle steady. I am wondering if TPS is bad? I just hate to keep buying new parts. I will try to check the TPS with DMM as soon as it stops raining. Any other suggestions other than TPS?