Hi all this is my first post on here long time member. I just recently sold my super clean 99 civic after doing a ton of work to it over the years and swapping it. Went about 3 months and decided I needed a honda again. So I bought a 99 SI on a steal of a deal. It has a low idle when cold and usually won't start/stay idling without dying unless I give it gas, if I drive it down the road and back it won't die on me but will idle very low (like 300-400rpm) Until it is up to operating temp and from there it will idle at normal 700-900 rpms. I would really like to get this figured out this weekend when I go home from school, I was thinking maybe IACV or bad battery or alternator?

Open to any ideas and willing to try it. I am mechanically inclined so just shoot, never had a weird problem like this before though.

Thanks again

 

USDM or Canada 99 Civic Si?

CEL codes?

 

USDM no cel's
runs very well after warmed up, no noises or issues. only has 126k on it too

 

clean the IACV and report back. over and out

 

Yeah that was the first thing I planned on doing when I get back home.