99 3.4L start up problem

my alero has 116k on it and every time i start it up it will A. start up fine, the rpms usually hit 1000 then go back down to 750 which is idle. B. start up and the rpms will hit 800, drop to 500, then shoot up to 1250-1500 for a second or two then drop down to 750. C. car will start up, hit about 600-750 and stall out. when this happens i usually try to give it just enough gas to make it hit 1000 rpm so it wont stall out and i havent found a way to fix it. ive changed the air filter, spark plugs, fuel filter, oil and it still has random times when it will stall out. but as soon as its started it runs perfectly fine with no random problems. the weather doesnt effect it because it did the same in winter as summer so its not any temperature problem. any info would be useful.

Welcome to AF.

Sounds the idle air controller (IAC) is either bad or just dirty. Remove it and clean the spring loaded pintle with spray carb or throtttle body cleaner and then lube with silicone spray lube. Be sure to get the carbon out of the seat and orifice where it mounts on the throttle body.