coneheadsracing

I've tried this before, and didn't really get anywhere. I've also searched and can't find anything for sure.

I have a 98 honda civic four door. Y7 motor. I want to go to obd I, as i am going to change the turbo setup in my play/hatch, so i have a lot of things that will swap directly into the four door for turbo.

I have an obd conversion harness, and tried plugging in a Po6 and a P05 neither would idle the car. Now i'm basicaly looking for what i need to change around.

Injectors? dsm 450's do i need the resistor box with an obdII harness and obdI computer?

Intake manifold will be obdI, any sensors that need to be re-wired, isn't there an extra idle sensor with obdII harness, or does the conversion harness take that out?

Distributor, i have obdI's laying around.

Anything else i'm forgetting, i run an y8 in my hatch, but that runs obdI harness obviously, so that was easy... just not sure what the obdII engine harness is going to do. Thanks for any help, if someone knows of any write ups on this that would be awesome too.

2redstars

the conversion harness you have most likely is amde for an ex model, and since you have a dx, you need to make one change for sure. are you using the iacv on the back of the manifold or the one under the throttle body? depending on which one you have you either need to change a couple wires at the ecu, or a in the conversion harness.
read this, it has alot of info
https://honda-tech.com/zerothread?id=1171263

coneheadsracing

That likely is the issue then. I have an lx, so it has that gay manifold, with the 3 wire iacv. I am going to be dropping in a different motor with a iacv on the back, so i'll have to rewire that plug.

I've used an obdII distributor in my other car, which was all obdI so i'm guessing i won't have to swap that out.

Anyone know about injectors though? Will i need to run a resistor like i did in my eg hatch, for the dsm 450's. I'm saying yes, because isn't the injector driver in the computer?

coneheadsracing

Searched on the injectors, obdII uses the same type injectors as obdI so i will need the resistor box for the 450's.

Hopefully put it in this weekend, anyone wanna confirm any of my findings, like people that have done this

2redstars

yes you need the resister box, or put inline resisters in.

0xenocron

All OBD1 Integra/Civic ECUs require the use of a 2-Wire IACV

Your three 3 wire will cause all sorts of wacky idling things but will generally run fairly normal.

Low impedence injectors = need resistor box
High impedence injectors = no resistor box

coneheadsracing

I've been trying to figure some things out before i rip out this motor. I re-wired the pins at the ecu, positive to the EACV signla for obd I. Took out the orange wire (-) only used with three wired IACV's and started the car. Didn't really want to fire up right away, and then shot to 4 grand and stayed there. If i unplug the IACV then its got a lower idle, but surges, as would be expected. this is on a cold motor. Chipped P28 ecu. I plugged in my P05 ecu same high idle.

I am switching to an obd1 intake which will use the 2 wire IACV, does anyone think or know if my idle will be normal then?

Lots of people have put y7's into obd1 cars, including myself, but i can't find many that convert the y7 over to obd1. I just want to boost it properly, i.e. chipped ecu, why does boost have to be soooo addicting, you would think one car would be enough