Idle Issue

[Dammit1323]

Hi everyone! I have a problem with my idle i hope you guys can help me. My car is running about 1k RPM not above or below. I tried to adjust the idle by unplugging the tps sensor and adjust the screw from IAC. I clockwise the screw and noting happen but when i counter clockwise the idle goes higher. I wonder is my IAC going bad?

Also when i turn on my e-fan and my lights I get this whistle noise. Can't figure out why is doing that. Can it be a some kind of Bad Ground issue?

My car is a 91 coupe KA24DE rebuild motor.
Has a Nissan Quest alternator, New starter, dual electric fans (Install a manual switch) , aluminum radiator, and a silvia front end (w/ triple projector headlights), No A/C.

[Jmoore124]

Whistle sounds like it may be a vac leak. Not sure why it would only happen when you turn on the lights other than the extra load from the alternator on the motor increases intake vacuum and makes the noise perceivable.

[WDRacing]

Can you not tell where the whistle noise is coming from?

Spray break cleaner all around the intake manifold and vacuum lines while it's running and listen for the idle to drop.

[Dammit1323]

Hey guys sorry for the late reply been soooo freaken busy. But the noise is coming from behind the motor especially when im driving. But i think your right Jmoore124 the alternator can be under extra load and might make the whistle noise. Ill try to figure it out. Thanks for replying. I appreciated.

PS im gonna make a video about the problem.