it is very specific in that it happens when something requires power from the engine at idle. Say you turn the wheel the idle drops when you stop it goes back to normal. Or the harder I brake when I come to a stop and the engine is at idle for a second while I am coming to a complete stop the more the idle plunges. Or if I have the AC on this makes all these problems worse. Putting the car in reverse also causes the idle to lower and occasionally stall. If I turn the wheel while putting it in reverse it has stalled. I was going to clean the throttle body tomorrow and MAF sensor, but I don't think that would cause a problem such as this would it?

 

All that stuff sounds normal to me except the stalling. AC pump and PS pump are both being turned by energy from the serp belt, when they're not on they spin freely, but when you turn on the AC or turn the steering wheel, they will cause the RPM to drop slightly at idle. Not sure what the stalling in reverse is about, maybe a coincidence?

 

also, have you looked for any stored error codes? just wondering if there are any issues with the throttle body/tps/idle control motor.

or sometimes a vacuum leak can cause idle stability issues.

 

I have checked for stored codes not too long ago. I didn't find any. But I used an OBD II scan tool from Autozone. I'm going to clean the throttle body any way. I'm doubtful it will help though. I will check for vacuum leaks as soon as I know where to look.

 

There are vac lines everywhere on the motor, they're about as big around as a pencil, the OEM lines are covered with woven cloth and are likely very brittle. I'd prolly buy some at AutoZone or somethin before you start fiddling with yours, as soon as i touched mine they fell apart in my hands

Just follow them around the motor and replace where needed (i just replaced them all). Also, there's a vac tank on the front of the motor, it's a little black sphere about the size of a softball, make sure its in good shape.