Hey like the topic says. I just dyno and tune my car and with my b20 vtec civic. This has never happen before. I turn on my headlights and the idle drops below 500 rpm. if i turn it off it comes back up to normal idle around 8500-9500 rpm at what it set at. Does anyone know a solution to this??? Is it a alternator problem?? I just broke my alternator belt the other day but replaced it. Need help please.

 

alternator belt is not tight enough or the battery is bad.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by infam0us &raquo;</TD></TR><TR><TD CLASS="quote"> if i turn it off it comes back up to normal idle around 8500-9500 rpm </TD></TR></TABLE>
I'd hate to see what your redline is set at. Is your IAC valve working?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by infam0us &raquo;</TD></TR><TR><TD CLASS="quote">...if i turn it off it comes back up to normal idle around 8500-9500 rpm at what it set at...</TD></TR></TABLE>...Wow, that must sound interesting idling in a garage or sitting at a redlight... WAHHHHHHHHH!!!!!!! How the heck would you launch?!

ok, back to the real world, it may be the voltage regulator...

 

sorry i meant the idle is set at 850 to 900 rpm around there the extra zero was a mistake.