Surging idle

[gerald holland]

I have the 2000 Expedition with the small v-8. A few weeks ago the idle speed started surging after I would slow down at a stop. It will rise and fall about 4 times and then it will steady out and be fine. Until the next time I came to a stop. Sometimes it will fall so far the engine will stall. I then start the engine and the idle speed is fine, until the next stop. I need help on this one.

 

[Don Hall]

May help (?): https://www.aa1car.com/library/problem_idle_surge.htm

 

[gerald holland]

Hi Don, I did replace the IAC valve and there is no change. Any help is appreciated.

 

[Yupster Dog]

I have the 2000 Expedition with the small v-8. A few weeks ago the idle speed started surging after I would slow down at a stop. It will rise and fall about 4 times and then it will steady out and be fine. Until the next time I came to a stop. Sometimes it will fall so far the engine will stall. I then start the engine and the idle speed is fine, until the next stop. I need help on this one.

Codes? clean air filter, clean MAF sensor.
Same tank of gas?
check vacuum hoses for leaks.
PVC valve, Check elbow on top and the rest of the PVC hoses (the original elbow disintegrates)

 

[Yupster Dog]

Why do you have three threads going about the same thing?
Refer all post to the one so everyone is not posting the same thing in different threads.
People want to help but not when you make it harder.