Ive seen the answer to this somewhere else but cant find it again. I just got my a/c working yesterday, and previously, my idle has always been seeking, from 800-1400 or so. Now that the a/c is working, I can turn the a/c on and get the idle to steady at around 1200. I have no bac, so thats probably part of the reason, but why would load cause the idle to smooth? Ive already checked and set my TPS, which itself was a bit odd. It falls within the specs, 1 at idle and slowely and smoothly tops out to around 5.2, BUT it reaches maximum at only about 1/3 throttle. Is that normal?

Anyway, what else can you guys figure it would be?

 

the BAC adjusts idle for loads on the engine like when you turn on the A/C. So, if you don't have a BAC then your idle speed will have to be set higher so your car won't stall when you turn the A/C on. You probably need to reduce your idle speed to around 1000-1100. When the idle speed is set too high, the ECU issues a fuel cut signal and idle drops. That's why you experience the "hunting" or "surging" idle from 800 - 1500 up and down....drives you crazy doesn't it?

WOT will typically be reached at less than 1/2 throttle. So, yes that's normal and you don't have to sweat it.