I have a 1987 4runner 22re. There is a loud noise coming from the AFM. When the flap moves it make a lot of noise. This started while driving and has caused a significant lose in power. I dont know the cause. Any help would be greatly appreciated.

The engine is rebuilt with a new head. I have tested all the wires at the AFM and at the ECU and am getting good readings. I have replaced the AFM with a remanufactured one. I have checked the TPS and it is set correctly.

 

Ok, is there dirt in there causing a scraping sound when the flap moves by hand? You can try cleaning it out if that is the case.