Hey guys, I got a problem with my 99 Civic Si, when it warms up up the idle bounces from about 1 grand to 2400. It's fine when it's cold, you can drive it around untill it warms up, then it idles funny and then throws a code, I can keep it from throwing the code by holding out the clutch while stopped and keeping the idle on 1 grand, but if I dont it idles funny and it throws the check engine light on. I dont have anything to read the code with, so yeah.
I just replaced the IAC and it didn't fix it. I just installed a new intake manifold that didn't work, it made the car idle way high, so I took that off and put my AEM fuel rail on, which did work. Everything else stock but the fuel rail. If you need any info about the car, let me know.

By the way, it's a B16A2.


Modified by vics_si at 6:37 PM 5/15/2006

 

I suggest you ask in the other civic forum. This is for the civic's and crx's up to 91.

 

moved...

 

i always here things like this with 99-00 si
i own one and i had the same problem.
i think is the p2t ecu. i upgrade mine to obd1

 

try this i hope it helps http

://honda-tech.com/zerothread?id=1564019

 

Nope, no help, that wasn't for my car. It was for earlier years.

Just any advice would be helpful.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by vics_si &raquo;</TD></TR><TR><TD CLASS="quote">Hey guys, I got a problem with my 99 Civic Si, when it warms up up the idle bounces from about 1 grand to 2400. It's fine when it's cold, you can drive it around untill it warms up, then it idles funny and then throws a code, I can keep it from throwing the code by holding out the clutch while stopped and keeping the idle on 1 grand, but if I dont it idles funny and it throws the check engine light on. I dont have anything to read the code with, so yeah.
I just replaced the IAC and it didn't fix it. I just installed a new intake manifold that didn't work, it made the car idle way high, so I took that off and put my AEM fuel rail on, which did work. Everything else stock but the fuel rail. If you need any info about the car, let me know.

By the way, it's a B16A2.


I have a similar problem on my 2000 si. When i start it, it warms up at a constant rpm (1500-2000) but then when i drive it and give it gas and let off quickly, the rpm drops very low and the car wants to stall unless i give it gas. I checked everything and i do have a aem fuel rail too. i cleaned out my throttle body and i still have a cel but i reseted my cel by pulling the radio fuse. it will probably come back. my throttle body i think is the problem of the idle surging but i also think it's my second o2 sensor, or a vacumm leak. I just need to get mine checked for the cel code. But other than that my car runs fine. I nailed down my possibilites to the throttle body, o2 sensor, or a vaccum leak. now i just need to get my car scanned to see whats causing the car to have idle problems. hope this helps cuz i wanna fix my problem too.


Modified by vics_si at 6:37 PM 5/15/2006</TD></TR></TABLE>

 

My B16A did the exact same thing. If you take off the throttle body on the backside there is a screw under a little brass like cover that vibrates loose over time that controls the flow of water. when it comes out it let's in to much water in and makes it rev up and down while idling.

 

So when u say the screw comes out, is it lost and u have to replace it or does it not come out completly and you just have to re tighten it?

 

Thanks for the attempts to help, but I just got done ripping the throtle body off and I found that there were no screws covered with a brass like plate, it must just be with the B16A's and not the A2's.

I really need to get this fixed ASAP so, again, ANY help would be appreciated.

And thanks for the help so far.

 

I have the same problem with my car. The idel would go down at idle, Cleaned out the IACV and its till there but I get a O2 cel so I am waiting to change out the first O2 the one on the header and hopefully that will fix it.