hey guys..i've tried doing some searching and i haven't exactly been able to figure out the HT search..

but the title is my problem..i'm helping a friend do a swap into his 99 hatch..and he's gonna be using my obd2a engine harness that's got all the jumpers needed to run an obd1 engine (dizzy, alt, etc.) but the main question is

can i use my obd2a harness into his obd2b car without any big problems..or would it be easiest to just wire it with the factory harness or sort an SI/EX harness?

thanks in advanced guys!

 

You'd be better off getting an SI or EX harness and going from there. The distributor and alternator connections from obd2a and obd2b are different.

 

the dizzy and alternator connecter differences between obd2a and obd2b don't really matter since the engine is and obd-1

i guess i should've refraised the question

because the engine is and obd-1...my obd-2a harness already has all the correct jumpers to be plug and play with the obd-1 engine....

will the obd-2a engine harness...plug into the rest of an obd-2b car without much hassle?

 

bump for some more input!

 

Yeah I ran in to this same issue with my 00 hatch w/ jdm b18c. Well since your car is a OBD2b, your engine harness needs to be OBD2b due to the ECU connections. OBD2a engine harnesses have 3 ECU connections and you have only 2 and one on the Dash harness. That is why you need to stick with the your factory harness.

So I'm guessing here but your dropping in a B series engine, your going to need to get a 99-00 b16a engine harness since it is a OBD2b harness with the old DIZZY connection.

 

the first part of what you said is what i was really looking for haha

but yeah it's an obd-1 b series that we'll be installing

 

^^ so chassis is obd2b and your swapping in an obd2a right? don't you just need to swap dizzys, run obd2b -obd2a conversion harness, and good to go? i also like to know how this works as well..

 

Im sure you can, but the connections on the 2 ecu's are differnt, so it would be easier to stick with the chasis wire harness.

So grab a obd2b harness and a obd2b-obd1 harness.

 

I just now got an account here; I am the other party that was involved in this debacle lol. I went ahead and bought an EM1 Harness. I'm using an obd1 B18C1, as well as it's obd1 p72. EVERYTHING is USDM.

NOW, this is a sticky by "katman". He says that the con to using an obd1 ecu in my car even with an EM1 VTEC ready harness, is that I need to wire in a vtec pressure switch. In ALL my research, I have NEVER heard of such. Is this true?

 

Oh yeah, I have an obd2b-1 conversion harness also; I've wired in a resistor box, and chanced my injector clips. The engine is built, and is running prelude 330cc injectors, hence needing a resistor box so I don't fry my ECU.

 

I have a 99 si wiring harness if needed. It came with my gsr swap but I have no use for it as I have a eh2

 

I have one too; I may talk to you about yours though lol, you never know when you'll need another harness. I plan on getting another Honda and swapping so...eventually I'll definitely want one.

 

that is already on the harness. you will have to wire up IAB (if you're using it) and change the connector for the IAT if you're using the one from the gsr.

i'm surprised you haven't got this swap over with, 5 months later.

 

Yeah; we just started doing it last weekend. I decided to not mess with it until I figured out this wiring thing. I modded the harness as needed (I thought) so I'm hoping that it'll be done and over with after I drop it in. I just now got the money to pay my guy for the engine. I thought I'd have it around when he first post this up, but I didn't; I was still in the process of getting all the parts together at that time, so when it was posted it was essentially a "Do I need to buy another harness or not" thread lol.

But anyways, I guess I need to check into this IAB/IAT stuff; never read about that stuff either.

 

I think I know what you're talking about. IAB is intake air bypass, and IAT is intake air temperature? I'm not using the stock intake; it's a skunk 2...no, skunkWORKS type R intake replica (legit product, reproduction of the type R intake manifold) so I believe these mods are handled. No need for the IAB, and the IAT is on the harness I believe; I'll figure it out. If not, a couple minutes of soldering and it's a wrap.

 

Hey ht just thought id post in this thread instead of starting one since my question is pretty similar....I have a 95 ls integra that's obd1. I want to put on a b16a2 head and go ls vtec but I have no idea what conversions I need electrical wise besides gettin a vtec ecu...can I just plug in any obd1 vtec ecu or does it have to be obd2a like the head? I heard something about the distributor having to match the ecu? What about injectors? Please help....

 

DON'T TAKE MY WORDS AS THE GOSPEL, but I'm pretty sure you'll need an obd2 dizzy, as well as an obd1-obd2 dizzy adapter because your dizzy plugs are going to be different. Also, the injectors will more than likely have another style of clip that's needed. If I'm not mistaken, a non-vtec ECU can be modded to run vtec. I have no experience with this, and I'm not sure if even more wiring conversion needs to be done. I'll do some of my own research and see what I come up with.

 

Sweet! Thanks for the input bro

 

You could use obd 1 harness, injector alternator and dizzy and hook up to a obd1 ecu. It doesn't matter what the head is originally(obd1 or obd2). The ecu decides if it is obd 1 or 2, not the dizzy, alt, or injectors. The connections are do change between obd 1 and obd 2 for the dizzy, alt, or injectors. I bought a 99 gsr swap for my 94 hatch and I am using an obd2 harness to hook up to the obd2 injector, alt, and dizzy but hooking everything up into the obd1 chassis harness and obd1 ecu

You also need a vtec ecu for a vtec motor. and stick with obd 1 dizzy, alt, or injectors since you already have them. You might need different dizzy for vtec but don't hold me to that one

 

I was told I could use my ls distributor if I cut part of it off. Also I was told I can convert my p75 for vtec. Just picked up a complete obd2a gsr head today instead of the b16

 

YUK. That's more wiring man. Unless you change the intake. Screw that dual runner intake lol. Anyways, Yeah, you can have the p75 chipped to see vtec and deal.with it. Bit once again, i think thats extra wiring. Alternator? Get an adapter plug. I don't think cutting it is goint to help in any way at all. Who said that?

 

Well I bought the head from some dude who owned his own shop. We leak tested it and it was all legit and when I told him what I bought the head for he said he's built lots of ls vtec's and that I could use my stock obd1 harness and he could re wire and chip my ecu with a type r base map for like $80bux. He said the intake would be fine except for one part but to just leave it unplugged. He said to cut one of the legs off the ls dizzy because its in the way of the vtec solenoid. Then he told me I need a gsr oil pump too when I thought I jus needed the water pump/timing belt. Idk how accurate he was that's why I'm trying some more input