Your gas may be old. Do you still have the problem after you have filled it up with fresh gas?
You may need to clean the injectors more thoroughly than that.
http://www.storesonline.com/site/598452/product/DI208
http://www.storesonline.com/site/598...001?src=google
Also the throttle body:
http://www.4x4wire.com/toyota/mainte...throttle_body/
New air filter and plugs?