Rpms dip in Neutral

I've had this problem going on for a while now. It doesn't happen all the time, it'll be perfectly fine for weeks/months at a time, then all of a sudden out of nowhere, whenever i shift into neutral, the rpms will dip down to about 500 like it's about to stall, then bounce back and forth a few times before it levels out at idle..., and it'll do that for a few days and then it's back to normal again. Not sure if it's a fuel problem or electrical, when it dips down the lights do dim, but I figure that's just cuz its almost stalling out. Just really hard to tell whats wrong cuz its usually running fine. Anyone have any ideas what could be wrong??:confused:

Your throttle body is dirty. Clean it.

And that is somewhat normal. The IAC (idle air control) valve does take time to open to adjust for the random change in throttle position.

Well, I got some throttle cleaner and gave it a good spray, hopefully that will take care of that problem. Won't know yet, because it stopped doing it the day b4 I did that. Thanks 4 the help

Well, I got some throttle cleaner and gave it a good spray, hopefully that will take care of that problem. Won't know yet, because it stopped doing it the day b4 I did that. Thanks 4 the help
you should take the TB Off and clean it. Not just spray stuff in there.

Thanks 4 the tip. I took the throttle body off 2day, and sure enough, just spraying that stuff in there missed a lot of stuff I couldn't see from the outside. Kinda funny how they say on the can to just spray it right in there if it doesn't do crap. I gave it a good cleaning and put it back in there. Seems to run better so far.