View Full Version : Power FC or alternator issue?

04-21-2010, 12:58 PM
I've been having an issue with my S13 w/ S14 SR20 trying to idle. It normally idles fine, but as soon as my altima fans kick on, my idle can drop to as low as 500rpm. I've tried playing with the idle settings in my Power FC, but it really hasn't made a difference.

I did notice that when the fans turn on, the voltage seen on my FC's hand controller can dip to as low as 12.8, but stays in the 13.2-5 range with the fans on. Normally has 14.0-14.4 with them off. Also just recently noticed that when my automatic seatbelts move or I press the brake pedal, the idle dips a bit. Battery is brand new.

Is this something alternator related? Ground related? Power FC? Its been driving me insane!

04-21-2010, 07:39 PM
Electrical load can lower your idle, but usually idle speed solenoid (IACV) kicks in to rise back up.
Does the idle rise when you rise in pfc-commender?
You may not have power to IACV or it's already running 100% duty.
Try to open bypass more.

04-22-2010, 12:55 AM
Actually I'll have to check that out. The idle does indeed rise to where I set it in the PFC. I'll report back tomorrow if I find anything wonky.