audiophile

Ok, I have already search the forum for an answer and found nothing.

I have a 99 civic ex that i just swapped from auto to manual. The problem is that after the car warms up, It idles at like 200 rpm. I know that the iacv is the problem. The auto iacv is a 3 wire unit that is under the throttle body. The manual iacv is a 2 wire unit that is on the back of the intake manifold. I am still using auto ecu with a CEL.

Now i thought up some options of how to fix it but I dont like trial and error. I was hoping that someone had some first hand experience with this problem.

Option 1:
I know that the auto iacv is completely different. There are 3 wires an orange, a black/blue and a yellow/black. The manual iacv has a yellow/black and a black/blue (which is in a different pin in the ecu). I was wondering if it would work if I disconnected the orange and moved the black/blue wire to the correct pin in the ecu. I have been thinking about this for a while, but i keep saying to myself that honda made 2 completely different setups for a reason.

Option 2:
Buy a mt intake manifold, throttle body, iacv, and ecu. I know that this would fix the problem, but it would take a long time to get the parts because I would not buy them all new because it would be kind of expensive. And I plan on buying an aftermarket intake manifold, throttle body and full engine mangement in the future.

Option3:
The most expensive of them all. Suck it up now and buy the aftermarket intake manifold, throttle body, and EMS. And of course the IACV. This option might be the most fun, but it costs over $2000.

The main reason for this post is to see if the first option is possible. If it is not possible, i probably will just go strait to option 3.

All help will be appreciated.

RedHackBatch

im guessing its the ecu...getta p28

civic97b18csi

Im in the same dilemma. In my case i will be replacing the intake manifold. Unfortunately for me i need to do this asap, because i have to pass emissions in less than 25 days. still looking for an intake manifold!! Already got the ecu thanks 2faz2paz! Good luck

salbaje

i would do #3 if you already have the cash. If not then i would say do #2 and solve that problem it can be annoying

allmotorsi04

option three seems will solve your problems, and in the long run you will be glad that you did it.....just do option #3

audiophile

The idle problem is more annoying then you think, I have a set of Hasport motor mounts (all three) WIth the stiffer race urethane. So when the idle drops low the car shakes so much the whole dash shakes and my teeth chatter.
Its terriable.

boostin4drcivic

i did a auto to manual tranny swap on my eg. the only thing i changed was the ecu. i used one from a manual car. i have the same intake manifold and everything. never had any probs with anything and has been running well over 3 years now. ive never heard of anyone having to change over an intake manifold in the process. i say just change ur ecu and leave everything else alone.

Quad-Damag

You have to change out the auto ecu for a manual one, or the car runs like **** + i belive u throw a code 70, something to do with the automatic sensor

audiophile

i already have a manual ecu on the way. I did not think that just the manual ecu will solve the problem. The auto and manual iacv are completely different. I did not know that teh manual ecu will control the auto iacv.

If i am reading your replies correctly you are saying that all i need is the manual ecu and i do not need to change the iacv.
Am i reading it correctly?

vizeta

hi audiophile, did u solve the problem? I read alot post regarding to this issue. some people say ecu some people say no. I think it's all becoz of we are using odb2 which is not for EG. let me know if u can solve this problem without replace the intake manifold. thanks.