Revs dropping when brake is pressed ?

[turbo-fever]

Right replaced the alternator on the starlet as thought that maybe the problem but still when I'm coming to a stop and press the brake the Revs drop to like 400 -500 it's even worse when the lights and wipers are on ? Has new decent battery as well any other ideas ?

Edited April 20, 2016 by turbo-fever

[aleximport25]

Is the Alternator belt tight ?

[MR-2]

Intake manifold VSV for idle don't work? You can test it with multimeter from, just google Toyota BGB info...

[turbo-fever]

Yes belt is tight and will check the vsv thanks MR-2