the rpms on my 86tpi iroc drop to less than 500, then the car will stall if i don't give it gas. this only happens when i come to a stop sign, or if it idles for more than a few minutes in park.otherwise, car runs great. checked for vacuum leaks, cleaned iac as per vader's detailed instructions, checked tps. what am i missing? no codes set. recently installed speedometer cable.

 

My thought?
SPARK! is weak.
OR Alternator.
Either way I'd say one of those.
Spark also equals timing chain, too. As in worn.
Rebuild distributor, too.
Coil?
Also check your battery cables to the ends.
Being in road salt areas tends to slowy destroy things.
Your car is twenty years old, expect things like this.
I know cause I'm once from PA

 

what ked says