My idle during warmup idles up and down up until it reaches operating temperature. Then it has a steady idle but it wont idle under 1500 untill i press the accelerator a little hard then it steadily idles where i have it set. My tps is set between 750-790. I've changed the old BAC valve which did function but the ohms resistance on the electrical prongs were reading too high. I replaced it with another working BAC valve with the prongs reading about 12.7 ohms resistance which is fine. But my car still has the warmup oscillating idling problem. Im thinking its the electrical connector that you plug into the valve but Ill have to recheck it. I dont think its a vacuum leak because I also had my neighbor who is a auto technician help me look for them with a vacuum gauge tester, but its possible I missed something. I'm running out of ideas to find what the problem is besides the electrical connector. Could it be something thats clogged that needs to be cleaned out?

 

If you press on the throttle and it lowers the idle after doing so then you likely have a throttle cable that's in need of adjustment as it appears to be sticking. What does the idle drop to after pressing on the pedal?

 

Well after it reaches operating temperature the idle will stay above 1200 rpm unless i press the pedal, then it goes to 750-790 and itll stay there. Sometimes when it goes to the rpm i have it set to, if i press the pedal a little and sustain it at a higher rpm, it may stay above 1200 rpms sometimes until i press the pedal hard again. This is all while stationary and not driving.

 

Chances are the throttle cable is not set properly.

 

That might fix that problem. If that works then the warmup idling problem is left

 

my car seems to do the same thing. but only on really hot days when stop at a light. the revs dont drop, they stay just above 1100 unless i put it in gear or touch the throttle. is there any other system in the car other than the warm up cycle that plays with the throttle? i can rule out throttle cable since the revs will drop when i put it in gear with out touching the throttle.

 

I am experiencing this same issue. Upon starting the car it jumps to about 1600 RPM if i place it in gear it drops to about 900. Then if i put it neutral again it jumps back up. After it is warm it sometimes jumps from 1100-1500 and drops back to 1100 and repeats. Any info would be awesome! Trying to keep this post high on the board seeing so many people i have spoken with have this issue.

 

Yeah, also when I put on the headlights, a/c and very little when i turn the steering wheel, the rpms go way low almost stalling but it doesnt stall.

 

That's pretty common. Alot of older cars do that. Just has to do with the engine being loaded.

 

The BAC is responsible for preventing the idle from dropping below 750 rpm for no longer than just a brief moment before it it supposed to stabilize back at 750 rpm.