i have a 93 honda del sol (si, D16Z6 engine) and the problem kind of
started with the cold weather; it seems that the idle
jumps up, then down sometimes when i start the car but
once in a while when i am driving it (the engine may
not be perfectly warm, but it is not cold either); if it is at stratup,
it may stall; i use the car for commuting 20 miles each way.

however, if i take the gas cap off, push the flap in (to
release the pressure), and let it like this for a min
or so, it is Ok for my commute... I noticed this stuff
when I tried (unsuccessfully) to change the fuel
filter, but as a side effect, I released the fuel
pressure.

My guess is that it has to do with the fuel system
(pressure regulator likely), but I will know more when
I measure the pressure, etc.

also, it find it hard to find parts for my car, and I don't have the bug $$$
to buy from a dealer; things i am considering, or i may need: fast idle thermo valve, idle air control valve, gaskets only for the above, etc. any ideas
(web stores?); i live near washington, dc.

If any of this is answered elsewhere, pls send/post the link and I will read it.
Thanks. Neko