P505 idle speed malfunction?

[Speed Demon]

I have a P505 code.
I pulled the IAC motor, tested it. Seems to be working fine.

What else is there to check?

Idle is high most of the time (1600rpm), but sometimes drops to 600 rpm.

 

[RunnerUp]

have you checked your MAF yet? what about power to your idle air control valve? you might be able to replace the valve, im not sure. hope that helps

 

[Speed Demon]

Haven't checked the MAF. How do you test that?

I have a cheap shop manual and it's not very comprehensive on what to cheap for idle problems.

The valve itself seems to be working fine. I'll check again to be sure it has power.

 

[RunnerUp]

The MAF takes about 10 minutes to remove and clean, heres a link

http://www.4x4wire.com/toyota/maintenance/tacoma_4runner_30k/maintenancep5.html