Does the engine idle up when first starting? It should run at a higher rpm when cold. If not, then your problem might be the IAC.
Before doing that though, check this out: You just changed the battery. Right after you change the battery, the ECU is reset and wants to figure out the optimum A/F ratio. Until it does, your idle will be strange, and startup idle is lower. Start the engine- warm or cold- and allow it to idle for 6-7 minutes. This will reset the A/F. The actual test takes 5 mins, but the ECU won't start it until after the engine drops out of cold start/high idle mode.
If that doesn't help, then we'll get on to some other ways to identify a potential problem. If it does work, then please note your idle speed. If you don't have a tachometer, then use the electronic odometer trick.
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Originally Posted by the user formerly known as ZX3_Chick
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