Accessories screw idle?
 

Weird thing. It seems like when I start using a certain amount of electricity my idle starts to oscillate. Example: I turn up my AC through all 4 positions and the idle is fine. But add the defroster and the idle oscillates from like 300-1,200. There's other combinations of things that do it too, sometimes AC alone will do it. I've got a PFC which controls the idle ok (except for this). The voltage also oscillates from like 12.8v to maybe 13.6v. Is this a bad alternator or battery maybe? Thanks for any tips.

The PFC compensates for electrical load. Did you do the initial setup with the PFC to have it learn the idle?

Read my PowerFC FAQ for more info -

http://www.clubrx.org/media/pfc/PowerFC_FAQ.pdf

You should have no idle surging at all - mine works great at all idle settings.

Dale

Oh yeah. I've had it for years now, last tuned by Steve Kan. I have all the idle settings the same right now -850rpm. What is the difference between the 3? I thought it was basically no accessories, then headlights, then AC. KD diagnosed it as an internal PFC problem but I'm not sure. I do have the buzzing ISC after shutdown at times.

I've been on the clubrx site, good resource. Some day I'll get around to repainting my calipers.

Replace your ISC....almost certainly it is the problem. I had a similar problem where the A/C caused the idle to keep dropping and replacing the ISC fixed the problem completely.

Do you remember the price? Seems like that job would be a pita, just getting at the darn thing.

I have one if you need.