Out of control idle

[ViewtifulCivic]

Hey guys. My car is steadily idling between 1500 and 2000. This is not cool. It's eating my gas mileage. Where I used to get 28-31 mpg, I now am getting 22-24. It's also a little annoying. My dad was the previous owner of the car and he said he had the same idle problem, and that was with the stock motor. Since I've done the swap, it has been idling high as well. Could it be one of the stock components that isn't changed during the motor swap, like the fuel pump or something? I've already messed with the idle screw on the throttle body and that didn't do much. If someone could, please point me in the right direction. Thanks.

[civic_boy91]

check for a vacume leak on the intake manifold, maybe there is a hole in a line/hose (like break booster,fuel pressur reg. line,) get a squort bottel with water and spray 1 at a time to see it if stops...if it dose you found your problem...make sure all the ports on the manifole are blocked off (if for some reasion they are not used...) or pluged in good. also if your throttle cable is too tight it will cause it to rev up and down when it warms up.

[ViewtifulCivic]

If my throttle cable is too tight, how do I loosen it?

[YZ125rider21]

losen it on the intake manifold...if i had a picture it would explain it all....should be top center of the intake manifold on front....just back it off it its to tight but you dont want really any play in it either...but its a simple task to do though

[superbluecivicsi]

other causes are:

map
tps
iacv

[Jos4DCivic]

Yup, check those .Could aslo try cleaning out EACV with some TB cleaner.



GL

[welfarepc]

i had the same problem with my old civic, try to unplug the power cables to the IACV (should be located on the driver side, and will have a green plastic connector piece). if the idle problem stops u know what the problem is. u should reset ur ECU after so u dont get check engine light.

when i unpluged mine, the problem stoped. i tried to clean it but it didnt help, then i sold the car. i wonder if u bought my old civic?? lol


Dan

[ViewtifulCivic]

Thanks guys, I'll look into all those things. My buddy said it could be because of my test pipe and exhaust pipe B. Could that be it? I don't think it is.

[civic_boy91]

Originally Posted by ViewtifulCivic

Thanks guys, I'll look into all those things. My buddy said it could be because of my test pipe and exhaust pipe B. Could that be it? I don't think it is.

i dont think so...i have stright pipe frome the header back and a cheap muffler (stright through..w/silencer) and my car idles fine