I have troubleshot everything I could think of and have only come to the conclusion that the setup/combo that I am stuck with just needs a jumper harness and a chipped ecu. I am trying to avoid the $250 cost of that since the car is nearly all stock.

Here is what I have:

1999 Civic EX with OBD2B wiring, dizzy, etc. 2 Wire Manual IACV
1997 D16y8 Engine with a 1999 Intake manifold (motor blew and previous owner replaced with a 97 version)
Wiring is all checked out tested at ECU and plugs.
Tried 3 different IACVs, tried blocking it completely,
Plugged every port and yet still the idle cranks at 3k RPM and surges after warm up from about 1500-2500...never had one this high before.

Only thing I am thinking of is the air ports on the intake manifold, however since the 97 heads dont have the small holes for air injection then technically just plugging the big port on top would just seal it off no problem.it should actually idle really low.

Idle screw turned in all the way.

Timing I am sure is a little off but with an idle that high I cant fine tune it.

At highway speeds car runs like a champ...low speeds it bogs, bucks, and breaks up.

Maybe using the P2P ECU is throwing the code since its actually looking for the air injection thats not there?

TIA

 

I'm almost certain that the 99 IM with the fuel injection air intake system is your problem.

 

Ok. Going to plug the holes tonight and see what happens from there.

 

Didn't the 99-00 have a cold start valve something.....that the 96-98 did not have?

 

Did you read the thread?

 

I did, but I was asking when he said "dont have the small holes for air injection" was that the cold start valve, were the holes for that?

Why was this valve added.........

I can say I have hard cold starts on my 96 ex.....was this the reason was added.

 

This is the answer to your questions:

Only 99-00 Civic D16Y8 engines have this air intake system.

 

Plugged the holes and good to go!

Since the 99-00 Engine set contains the fast idle valve in the thermo housing I guess I could have opted to install a 96-98 throttle body however it idles perfect and runs like a dream so good to go.

Thanks RonJ@HT for reassuring I wasnt plugging the holes and scraping off another gasket for no reason!