See if I can get some help on this.I just got done swapping
a jdm b18c in my 94 ls.I used an adapter harness from
rywire.com and used my engine harness from my Ls..

Wired it like so.
A4-vtec soleniod-black
a17-iab solenoid-red
Iab 12v wire-yellow i tapped the yellow black wire
that leads to A25 with the yellow wire from the harness.
D3-knock sensor-white
D6-oil pressure switch
There was also a ground wire on the adapter harness I bolted it to the thermostat housing.

Now my problem is my iab is not working.Its stuck down in the open position.The rod is vertical.I pulled the #13 hose off the dashpot and put my finger over it and i dont feel any vacuum.I checked all the hoses and they are all in the right place.I hear my vtec at 4400 but I hear nothing at 5800 like your supposed to.Id really like to get my iab working so I can get the full potential out of my gsr swap.
I just wanna make sure its wired correctly too.
Here is the rywire harness
http://rywire.com/store/produc...98056

 

?

 

are you using a p72 ecu?

 

yes jdm p72

 

If your iab is stuck open, which isnt so much of a bad thing, you wont hear anything at 5800, but, you wont really be losing anything either. In this case of how your iab is opperating, you might sacrifice a little low end drivability, or maybe a little rougher idle, and if you do I doubt you will even be able to notice. Now you want the iab valves to be closed when the car is idling and when in the powerband of the lower rpm's so when you do hit 5800, the butterflies will open and you may hear that extra so called "dual stage vtec" sound that your looking for. First I would check all the vaccum lines you hooked up and wires that you added, again. Then have someone sit in the driver seat and rev the motor up into the higher rpm's. Watch the mechanism below the dashpot that controls the position of the butterflies to see if it is working. It should snap open really quick and stay open only as long as you give the car the right amount of gas and hold it at, or above that certain amount. What happens here is that when you rev the engine up to a certain point or higher, almost all of the air that was going to the vaccum ports is now being sucked straight through the intake manifold and into the head and then down into the engine leaving little or no vaccum pressure in the manifolds surrounding vaccum ports. In turn, this leaves no pressure in the vaccum line that leads to the dashpot inwhich the vaccum pressure passes through to control the iab valve to either open or close. This valve will now open because of this lack of pressure, and stay open as long as there is no vaccum to suck it back closed. This valve also controls the opening and closing of the secondary butterflies. Since the iab valve just opened because of lack of vaccum pressure the butterflies will open as well. When you let off the gas and pressure returns to all of the vaccum lines, the force in the vaccum line that attatches to this same dashpot will suck the valve closed, closing the butterflies. If you see this little rod below the dashpot move back and forth between the ups and downs of the rpm ranges that your observing then the iab is in fact working fine. Or, another way to check to see if your iab is working is to unplug the vaccum line connected to the dashpot and this will also cause the valve to open. Without vaccum, the iab will be stuck in the open position. When the vaccum is hooked up, the valve will be sucked closed along with the butterflies. The valve and butterflies will only be opened again when the vaccum presure is released caused from either disconnecting the dashpots vaccum line like I just told you to do as an easier way to check to see if ur iab is working, or by giving the motor full throttle and revving high enough to cause this lack of vaccum pressure phenomenon that will open your secondaries and let your dual stage vtec be heard. And put your finger over the hose when you check for vaccum, not the dashpot. The dashpot does not suck the air, its the other way around.

I had a usdm gsr in my 91 integra and I didnt run the iab. I took the whole iab unit completely out of the intake manifold and bolted the two intake pieces back together. Then I got rid of the black box with the iab sensor and the vaccum lines. In the end it all made for a cleaner look, two less wires I had to wire up, and no need to make sure the vaccum lines are all correct because there was no longer a need for any of them. And possibly, it gave me a little extra power. Because, without the big iab plate sandwiched between the two intake halfs, the intake manifold will be reduced in length. This shortens the intake runners a little bit, resulting in higher air velocity, and decreases the space and volume of the intake manifold, causing higher air density. By customizing the stock gsr intake manifold like this you are making it so that it will now make more power from the mid to high rpm's and especially in the higher rpm's that the power from vtec relies on. The power you will gain will out weigh any loss of low end power, fuel economy, drivability, idle stability, that is, if there is even any loss at all.

I have read articles and heard a few people say that the gsr is the worst of stock honda intake manifolds and the least desirable because of this dual stage design. I think that iab is a good functioning mechanism and is more suited for fuel economy and emitions control purposes. Something we all are not to worried about on a performance motor that requires more air and fuel as its power is to be increased. Iab will just hold any performance motor down in the long run. Because, who is going to run their stock gsr intake on a motor that they built that has everything else done on it besides the addition of lets say, the single stage design intake manifold that skunk2 makes. Skunk2 is one of the most trusted product company and supporters of aftermarket honda parts. They didnt use " dual stage vtec " for a reason in their design of an intake manifold. And for as far as I know, no other brands that produce intake manifolds utilized iab and its concept of electronic/vaccum powered air intake control.

So if I were you, I'd do what I did and remove the iab system entirely. I had zero problems with my intake setup after I removed everything. All my friends said my car was going to be slow because i was just puttin a gsr into a DA, they all said DA's are supposedly heavy and i was going to have more trouble getting it to go fast than if i were to just get a hatchback or something. All i had done to the motor was some dc 4-2-1 headers, stage 2 clutch and pressure plate, an air intake, chipped pr3 ecu, any my customized gsr intake manifold. I raced two 92-93 integra 1.7L gsr's and beat them both by a few or more car lengths, smashed on a vr6 jetta with some bolt on mods, and i know i beat a few other people, i just cant remember what else i raced while i had that motor in. I Hope any of this helps out.

 

Thank you N-i-C-c-O-k-N that was very informative.I do want my iabs to work for now.Then maybe a skunk2 manifold later.

I checked it again today and the white piece of plastic came off the harness plug that plugs in the iab solenoid.The plug still goes in the solinoid.Thats my best guess right now why it isnt working.Would that keep the voltage from the solinoid?I do still have the wire harness from the swap.I could take the white plastic piece out of the solenoid with pliers,cut the plug off and put a new one on if you guys think that will work.

 

No I dont think that white piece would prevent anything from working. The white insert is just a protective guard and it helps the pins to stay in place. I just had an incedent with one of those white inserts causing a problem in a swap I did for a friend of mine. His vtec wasnt engaging and neither was his speedometer working. I checked the speed sensor plug and it wasnt snapping all the way down onto the sensor. I pulled it off and took the white piece out and then plugged it back in. This time it snapped right down. After that the speedometer started working and so did the vtec. Now maybe that white piece got damaged or something or was just a little different from the single tranny speed sensor that he had it on before. Since I like things to be perfect and it kinda bugs me not having that piece inside there, I might go back and try to get a different white insert to work later. But for the mean time, everything is working fine without it. So your sure the iab isnt working? You tried unplugging the vaccum line and all that? Nothing happens?

 

Well i tried another plug with the white piece and some for some damn reason it wont snap in but it does snap right in without the white piece.I put a test light in the plug and
turned the key to on position and it does get power.I pulled the #13 hose off the dashpot and it gets no vacuum.The only thing I can think of is buying a new vacuum tank and solinoid and trying that.Would it make your car rich if your iab's are not working?

 

Ok i got it working for reference.On Jdm obd-1 ecu's One wire goes to A17,(It switches power like usdm obd-2.And the other wire goes to body ground.Pulls good now

 

hey, i have this EXACT fuggin problem. My iab does not work. I tested everything. So your saying that you took the power wire that was on ywl/black and grounded it instead and now it works????

i tested the check valve , i have taken the wire a17 off the ecu, and had the other wire at power and when i grounded a17 they opened. that means to me that everythings working, the ecu is just NOt TELLING the iab;s to open.

SOOO, a17 and the other to a ground right????

 

Got it figured. Hooked one wire to ground, the other to a17 and walla. Hooked up a vacuum guage and got on it, and it opens.

Heres the thing i think some people dont know. When the car is off, the iabs are sitting open. When you start the car, there is about 25hgs worth of vacuum that closes the iabs. Well, when you hit that 5750 rpm mark, the vacuum canister trips the VSV valve and stops all vacuum and boom they open.

Neat neat. Feels like a new car up top now. ahaha..