Either when my engine is cold, or hot, at first start-up, i would have to crank the engine twice to get it started. But once the engine is started, my idle speed would go above 1000 RPM; even when the engine is heated to operating temperatures. When i adjust my idle back to reconmended specs; after a while, it would go back up again. Creepy

 

I would run some gas cleaner to start. It fixed mine. Some times the cold start injector gets cloged.

 

I already put in Redline's fuel system cleaner at my last oil change. This problem is starting to creep me out.

 

I'm not sure if this will help, but I've got an 01' Taco with a 3.4L and it began to idle rough a few months ago. As I attempted to troubleshoot it over several weeks, the problem progressed to stalling out while trying to seek idle after warmup. Finally, I found that Toyotas have problems with their Idle Air Control Valves (IAC) which tend to gum-up over time preventing it (the valve) from operating properly. The gum-up is a byproduct of the EGR system and/or cheap gas.

The solution is to remove the throttle body (4 bolts, 3 hoses & throttle cable), and on the underneith side held on by two bolts is the IAC. simply remove it and you'll see the black gummy carbon deposits. Soak it down with a good cleaner (I used DeepCreep by Seafoam) and scrub it with an old toothbrush. This completely fixed my idle problem.

Good luck.