Hondata

kaj and RMS
Guys I really appreciate the help you are providing. I wish a Hondata tech would have been just as helpful.
Unfortunately I am still without a Hondata S300 in my car. I am at a point of reevaluation the use of Hondata in my car.
Option #1- A special prepped P28 ecu would work.
Option #2- Modify the OBD1>OBD2 wiring harness.
Option #3- Sell the ?95 P72 ECU, ?94 P72 w/S300, wire harness on ebay and get a standalone ECU.

a modified civic ecu would be an easy way to go. hit up RMS. i'm sure he has some laying around. in fact, i used to use one of them. that will put an end to your problems.

how would modifiying your obdI-obdII harness work. that's interesting. or were you considering the relay option?

standalone is cool... but big money. i'd love AEM, but i don't have an extra $1000+ to spend :(

also, it's not really a hondata problem, so there isn't much they could have done, ya know? either way, good luck. i hate having problems while trying to get a car running. let us know how it goes. i'd like the last post of this thread to read "hey! i got it running. all is well now "

If you wish to retain the knock control then the solution is to use the P72 and add the relay...adding this relay is not really all that complicated and will cost about $10 to do yourself.

If the knock fuction is not something that really maters to you, then the modifed P28 will work fine.

if you are set on a p72 without a relay i CAN mod the p72 to change the polarity (it's just not cosmetically pleasing :) within the ecu.) the relay is really the best route for you though (if you send me the adapter harness i can add the relay if you're not comfortable doing the mod).

i can promise you that it is impossible for a stock obdI p72 ecu to operate the iabs in a stock obdII gsr.

RMS
What are the details of getting this relay installed?
Part numbers.
Which wires to splice into.
I should be able handle this.

i'll put a detailed post tonight

A17 is the iab control. cut this wire in the center (half way between the ecu plug and the harness plug) of your adapter harness. connect the ecu side of this wire to one of the relay's COIL terminals.

connect the harness side of A17 to the N.O. terminal of the relay.

A25 is ignition power. tap into this for the other COIL terminal AND for the COM terminal.

it would be preferable to use a relay with a built-in diode

hope this clears it up.
vernon of raver motorsports

RMS wrote:A17 is the iab control. cut this wire in the center (half way between the ecu plug and the harness plug) of your adapter harness. connect the ecu side of this wire to one of the relay's COIL terminals.

connect the harness side of A17 to the N.O. terminal of the relay.

A25 is ignition power. tap into this for the other COIL terminal AND for the COM terminal.

it would be preferable to use a relay with a built-in diode

hope this clears it up.
vernon of raver motorsports

that actually sounds really, really simple. hey, vern. do i have permisison to post this as a "how to" on FSR? i doubt anyone will get this technical.. and i know it may undermine future business for ya.. so i'm asking before i do it. FSR is a lot different than hondata ;)

go for it... the community can add it to my tab :)

Does this also apply for an OBDII JDM b18c (GSR)?

Thanks

Ok, found some information. I thought I had remembered seeing this, just didn't remember the link. I wouldn't recommend doing this unless you know what you are doing. Proper soldering and de-soldering equipment should be used. I learned this the hard way...

strider wrote:Does this also apply for an OBDII JDM b18c (GSR)?

Thanks

i believe that was the ECU in question, yes. GSRs are the only ones that have IABs.

notice the author of that how-to on that link is deluded? that's me :)

Cool. Now I know who to go to questions with. ;)

Aman, you have a better way of fixing your IAB issue w/o a relay.

On you 99 GSR the IAB solenoid connector will have two wires. One will be a Black and the other will be Red with a Blue stripe. As mentioned above the ECM control is reversed. The logical thing for anyone would be to install a relay but they activate slow and will cause your RPM activation to differ from your dialed in RPM changeover. The Black wire is simple ground and the ECM on the 99 GS-R sends a 12V output to activate it. The 94 GS-R soleniod has 12V going to the solenoid at all times on the same terminal (different wire color but that doesn't matter). The ECM grounds the other wire to activate the solenoid. I would simple recommend that you cut the Black wire from the harhess and tie that wire to the soleniod into the Black with yellow stripe wire from the EVAP purge soleniod located on the top of the intake manifold.

This sould fix your IAB control issue.

BTW IMO, the AEM EMS is a problem waiting to happen. This unit's datalog says one thing but does something else all together. IMO, its NOT a standalone. Whats worse is that AEM will never admit to any problems it causes and always blames the installers even if they were trained by EFI university saying that they didn't go to their training course. When Motec, Autronics, Bosch racing, Pectel, and various other REAL standalone ECU producing companies recognize EFI university as the training gounds for tuners.

Joe