i can't figure where to wire the IAT in. It isn't referred to in any of the dpfi-mpfi guides i saw and i'm 95% sure that there is no plug for it on my std harness. Any help would be appreciated.

 

Yes there is.


http://www.50mod.com/fourthgenhatch/mpfi.html

 

uhm.. i didnt even hook/wire mine up.. runs fine?

 

[QUOTE=shivern]Yes there is.


http://www.50mod.com/fourthgenhatch/mpfi.html[/QUOTE]

FYI, I moved all of those guides to a new site, http://www.4gcivic.net , if anyone wants to add something let me know.

 

actually, i have no plug at all on my std harness for the IAT. it's not like i can't find the plug or don't know where to put it. what i need to know is where i should splice the plug in onto my std harness.

Also, i have a surging idle at about 1100-1400, would the IAT being unplugged cause this?

 

LOL, all of the harnesses have them. I have done about 100 mpfi swaps, and have seen them on all of them. The iat is a red/yel and grn/wht wires with a white plug. Its in the grouping with the injectors, tps, and eacv wires on the dx harness.

Yes you need to run it if you dont want a code.
Ryan

 

i know i need it, i was just asking if it would be the cause of my odd idle, and i think it is.

i know that the plug is supposed to be there, but it isn't. i think its missing because i have a std harness, not a dx. i looked on my old std manifold, and their is no plug on the manifold like the IAT plug on it.

so now, i am going to splice it into the harness. the red/yellow wire goes to the C5 spot at the ecu, according to ecu pinout diagrams. my guess is that the other wire connects inline with another sensor, but i don't know.

Where does the other wire go to?

 

the grn/wht is a ground, you can splice it into the grn/wht on the tps

 

thanks a lot. i got nothing better to do tomorrow night so i'll finally get my car running again. i miss my car after a day without her.

 

an update. i actually had my iat wires going to my eacv. i'm switching them now to see if this solves all my error codes.

 

so where is your eacv then

 

well, here's what happened. the IAT plug was different on my 91 std and the 89 manifold i was using. i extended the IAT plug on my harness instead of the EACV plug (they looked exactly alike), and i was not using the EACV plug.

i figured out that i had them wrong when i looked at the wire colors. then to double check and make sure i'm right, i checked the resistance between the ecu pin and the engine bay plug to make sure it was the same wire.