1999 Civic EX, D16Y8.....
The engine is stock, 280,000 miles, runs well, been kept up religiously by previous owner, we've had it a year and put a few thousand miles on it without issue.
It started having a strange issue.....when its warmed up, if you feather the pedal to just above idle, it starts oscillating, almost like its hitting a rev limiter just off idle.

Having said that if you mash the pedal it revs out fine. It will blow down the road just fine.....this symptom does screw you up when trying to pull off from a light easily....(its a manual), as you ease the gas on to pull off, the RPMs start doing that, and it makes things rough as hell.

We did get an IACV code, P0505, but we did get it a couple weeks before it did this....and we did just clean it out really well and it didnt make the symptom go away, maybe the valve is just bad? we did also read that P0505 could be any idle issue, and is not exclusive to IACV? not sure....
we will reset the code and see if it comes back.

Any thoughts about this symptom? (Video is attached)
Heres the link to the video

https://www.youtube.com/watch?v=-9q4...ature=youtu.be

 

Sounds like a potential TPS issue.

 

I took the IACV off again and put it on the bench and cleaned it out again, hooked it to a power supply and verfied the plunger works...shot some PB blaster in it and worked the valve back and forth a good many times, and then blew it out with air really well. Fixed that symptom.

It still has one other hiccup that I will make another post about soon.

Thanks all!!

 

Can I get an update? I am having this exact same issue and it's been the bane of my existence as I feel like I've run out of things to do.