Flucating Revs when cold
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Flucating Revs when cold
(2001 Stock S2000 with 132k miles)
I've had this car for almost two years now with almost no problems! Today, though, I turned on the car and idled for a little for warm up the engine since it was a bit cold. After around 15-20 seconds, the revs started fluctuating between 1,500 and 2,500 RPM's constantly. With only about a half second between pulses. I ended up shutting it off and briefly checking a few of the lines but nothing looks inherently out of place, not obvious cracks or leaks. Re-started it and not surprisingly, it started again after about 15 seconds. I haven't done anything under the hood recently. I drove about 200 miles last Sunday and it was perfectly fine and haven't started it again till now. I do notice that sometimes, after revving in idle, the RPM's will drop pretty low, then go back to ~900RPM. Though last week it did finally stall for the first time.
I'm pretty new to the whole diagnosis part but I'm guessing it has to do with either the IACV or a vacuum leak somewhere?
What should I start looking into?
Thank you!
Here's a video of whats happening
https://drive.google.com/open?id=0B5...VA0Z2NCaWRXUzA
I've had this car for almost two years now with almost no problems! Today, though, I turned on the car and idled for a little for warm up the engine since it was a bit cold. After around 15-20 seconds, the revs started fluctuating between 1,500 and 2,500 RPM's constantly. With only about a half second between pulses. I ended up shutting it off and briefly checking a few of the lines but nothing looks inherently out of place, not obvious cracks or leaks. Re-started it and not surprisingly, it started again after about 15 seconds. I haven't done anything under the hood recently. I drove about 200 miles last Sunday and it was perfectly fine and haven't started it again till now. I do notice that sometimes, after revving in idle, the RPM's will drop pretty low, then go back to ~900RPM. Though last week it did finally stall for the first time.
I'm pretty new to the whole diagnosis part but I'm guessing it has to do with either the IACV or a vacuum leak somewhere?
What should I start looking into?
Thank you!
Here's a video of whats happening
https://drive.google.com/open?id=0B5...VA0Z2NCaWRXUzA
Joined: Oct 2008
Posts: 1,113
Likes: 51
From: San Francisco
I've seen that with a dirty or stuck rotary in the IACV valve -- follow the instructions to completely open, clean, and spin freely per this thread
(https://www.s2ki.com/forums/s2000-under-hood-22/shaky-idle-895678/page2/#post20975325).
(https://www.s2ki.com/forums/s2000-under-hood-22/shaky-idle-895678/page2/#post20975325).
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