So here is the deal, I have searched and searched all over HT and other various sites for IAB wiring. I studied the helms wiring diagram and have hooked everything up correctly.

Currently I have the Black wire connected to a switched +12v source. The pink wire is running into A17 on my s300 P72 so I should have IAB support. The way I am understanding this is A17 should put out a ground signal to complete the circut to close the short runners via vacuum... However the issue that I am having is A17 is not giving me a ground, and then when i invert the signal through sManager the signal is not strong enough to open the solenoid for the bypass valve.

I did some trouble shooting and used a good ground to see if the solenoid does infact work, which turned out to be good. Solenoid opened and created vacuum to the diaphram.

I could be missing something super simple here but im thinking that A17 on my ECU is somehow not functioning correctly and its driving me nuts. If there is something I can do to get my IABs working please feed me some info lol.

Also forgot to mention that voltage that I am getting with A17 inverted through hondata is peaking at ~9, what i mean by this is the voltage on my multimeter is variabley changing anywhere from .35 - 9v, normally hovering around 4.5-5v. W/o invert I recieve no signal at all, no ground no power...


OH GOD HELP!

 

Bump

 

take the butterfly plate out, you'll make more power across the board.

 

Wrong, you'll lose power in the low end and midrange. The top end will be the same. So over all, a worse ride.


OP you problem is you need to add a relay to your OBD2-OBD1 wire harness. Soon as my tuner did this the IAB worked perfectly. Sorry I can't give you specifics put I believe on HONDATA site or there form they have some details about this.

 

If you simply disable them then you are correct; however, if you remove the butterfly plate completely you will pick up power across the board.

I have dyno tested this many times as have lots of other people.

 

If butterfly assembly is removed or open all the time you have a short runner configuration. Good for top end, but it will hurt low and midrange.
So when people changed out there GSR manifold to a Skunk2, single runner and complained of losing power in low and mid it is an issue with the tune not the manifold?
Please post these dyno plots you speak of, I am very skeptical about your claim. I would bet the only change wasn’t just the manifold in most if not all of those cases.

 

The whole system is OBD1. Its a F22 harness that i tried to add IAB to through A17.

 

if they are disabled they are OPEN, not closed, it takes a constant vacuum to hold the iab's shut.

I'm looking for the last one I did on a stock h22, ill post it when i find it

 

Your right about the disable part, brain fart. Lets see the dyno when you find it. Got to edit my earlier comments.

 

none of the links are good anymore and i dont work at the shop where i did the dyno tests anymore so i dont have access to the files.

I am not making this mess up, it works and its been tested many times.

 

Are we talking about H-series or B-series? I have extensive information and personal knowledge on the B-series GSR manifold. But if you are referring to an H-series I would be a bit out of touch. I would like to think the conditions are the simlar but there is such a large stroke and bore change I would expect the dynamics of the manifold to react differently..

 

I have done most of my testing with h-series.

the only test i have done with a gsr manifold started with a car that never had them hooked up, we took the spacer out and picked up about 8ft/lbs from 2000 rpms to redline, very similar to what i saw with the h22 stuff

with butterflies in-place and working = good power down low, ok power up top
butterflies in-place and disabled = crap power down low, same power up top
butterfly plate removed = good power down low (read: about the same as w/the butterflies working), really good power up top.

basically by completely removing the spacer you pick up everything you lost by disabling them down low, AND get some extra up top.

 

Removing the plate would shorten the over-all runner length and remove a turbulence point in the runners, the valve. So the top end increase makes sense.
Not sure about the down low power, maybe a little, 2-3, over the butterflies in-place disabled.

The idea of removing the plate is actually a very old idea, early 2000's.
Many people just remove the GSR manifold and place a single runner now looking for all that peak power. I found it nice to make at times making 10-20ft-lbs of torque over these people with a similar set-up and great torque curve

 

With the s300 installed on my P72, is it possible that a different pin controls the IABs? Im begining to think that a17 is malfuntioning, As i can neither get a good ground source out of it or a 12v power source.

 

OH_1fstgsr already said you have to wire it up with a relay. If you got it to work but there wasn't enough power, that means you're trying to pull too much current through the ECU and you might even fry it. Use the signal from the ECU to turn on a relay.

 

Lets summarize what we know.
P72 ECU OBD1 and the IAB function works, correct?
F22 wire harness, what year? Is it OBD1 or OBD2? And why are you using this?
The solenoid and canister the vacuum lines come from that attach to the IAB, what year is this, OBD1 or OBD2?
Honda’s electrical system changed from sinking to sourcing at one time. I can’t remember when this exactly took place but this why you would need a relay.

 

I decided to try the Purge valve pin a20 instead and run a relay. IAB are funtioning correctly now.

The IAB pin a17 is OBD1 but was sending a 4v signal, I will eventually get a relay that can support low voltage to 12v source, but what baffles me is that and OBD1 ECU should send a ground signal if im correct?

The reason that im using a F22 harness is that is what came in the car when I purchased it. Everything including the swap was done at the time just not the IAB hook up. The harness should be OBD1 as it came out of a 94 and i believe honda switched to OBD2 on the prelude around 96?