Originally Posted by Omniscient
The idle bounces when that sensor is plugged in. When I take the plug off it goes away. Then it idled up to 3k. So I plugged the sensor back in and the idle went down to 2k then bounced repedidly up to 3k. I took the plug off again and it just went back to 3k. A little hard to follow if you weren't there but I have a feeling it's that sensor. Not totally sure though.
I know on Hondas, the "fast idle thermo" valve causes bouncing idles. You'll start your car hand have the engine surge up to 2500rpm, then back down to 1000rpm, and up again, and down again. It's like someone was rev'ing the engine.