I just installed a short ram intake and now I notice that the idle is a bit rough. When the car is at a dead stop, it idles around .75 x1000 rpm. It idles at .75 for a like 10 seconds and then the tach drops down to .5 and bounces up to 1, and it keeps on doing that over and over. Anybody know why? Suggustions?

 

clean ur MAF sensor, or make sure u installed it correctly, also reset ur battery, and let idle for 10-15 min after...

 

What do you mean by ".75x1000rpm"? Mine usually idles about 750rpm, but will sometimes jump to about 1200rpm on it's own.

 

Did you reset your ecu? if not its still learning your new mods.

 

What I meant is 750 rpm. .75x1000= 750 rpm, didn't mean to confuse you

 

No I haven't reset the ecu yet, I'm still trying to find out what to do first, how do you reset the ecu?

 

Disconnect the battery for a few minutes and then re-connect it. Turn the car on and let it idle for 10-15 minutes.

750rpm is normal for idling....but dropping down to 500 is NOT normal.

.......and neither is jumping to 1200RPM like FijiBlueFG2 stated.

 

The battery being disconnected during the install was all you needed, but you have to let the car idle for 10+ minutes like what everyone else said. As for you idle, I have the same number. I get the occasional extra rumble or roughness when my a/c is cycling.

 

If I disconnect my battery, won't that make the radio not work?

 

yup, you'll have to enter the security code. should be on a card in your glovebox. if not you'll have to call the dealer.

 

I disconnected the battery and let it idle for 15 mins, it still does the same thing. The idle kept bouncing in that 15 mins idle. Any suggustions? Its an 07 civic si, its only got like 8k on it, any help would be much appreciated, thanks.

 

are you getting a CEL ?

i worked on an 03 RSX before that had a similar problem. once it warmed up, the idle would start hunting. rpms going from 750 to 2k. at first i didn't get a code. but got one later. ended up being the rotary air control valve. (similar to idle air control valve) after i replaced it, it was fine.

i woould make sure that it is plugged in and the wires aren't knicked or anything.

dunno if it is the same problem that you are having.

check your coolant level. i was told that low coolant could cause idle hunting.

you can also do a search on "idle hunting" turns up quite a few hits on honda-tech.

hope this helps

 

Remember the a/c will be on if the defroster or def/floor buttons are lit up...... even though your a/c light isnt on. there is a way to turn it off but i forgot. I think its in the manual.

 

Yeah, I'm not too worried about it. It seems to happen when the fans kick on.

 

id rather removed the back up fuse but either way is fine. then wait awhile like everyone says. put everything back. now make sure everything is off: a/c, headlight, hand brake is up, audio off, etc. and start up your car. then let your car sit there and cyle the fans twice. your idle learn will be complete and the computer should have made compensation for the accessory. if you car has tpms id recommend the back up fuse method because I don't want to go though with the whole TPMS initialization process.