Probably been covered before, but I couldn't find anything good with the search.

I know everything it seems about swaps in OBD2 cars, but nothing about OBD1 cars.

Say I get a 92-95 hatch. Plan is for a nice engine, one that is newer, and that means OBD2.

I hear the distributor, and injectors need to be OBD1 pieces.

I am curious...will the rest of the sensors just plug right in then, or will I have to do some modifying?? Such as switching sensors, or switching plugs???

Plus, how do you remove the pins in the OBD1 ECU connectors??

 

Before someone else posts it:

 

You can run the complete OBDII motor (all components) but use the OBDI ECU. Just like the pic above I can back that up because I did that type of swap 3 years ago (99 B18C1 full OBDII into a 92 VX using OBDI P72 ECU) and people told me I was lying, full of ****, etc. Well, it's now 3 years later and the car is still running strong with no CEL's or any problems whatsoever.

 

same here - 98 or 99 GSR motor w/skank2 intake mani w/chipped p28

no wiring for me

94 VX btw

 

huh?

Ok..what on the OBD2 harness connects to the plugs in that pic?? What about the OBD2 ECU connectors? They don't do anything or have to be switched out or what?

Probably simple but I am confused....it would be nice if someone elaborated on this.

 

you might want to read their post again.. I totally understand

 

Ok mister know it all. Tell me what those plugs in the pic are then.

 

what they are saying is, is that if you get an obd2 motor you can stay odb1 by utilizing the wiring harness from the ecu to the where the plugs meet the engine wiring harness....when you get your new engine, the wiring harness will plug into the existing harness that runs to your ecu...in turn you'll have to get an obd1 version ECU of the motor you are planning to get...for example...if you buy an 96 obd2 ls motor, buy a 94-95 obd1 p75 ecu... or if you're getting a obd2 b16a2 Si motor, use a chipped obd1 P28 ecu. i hope you understand what i'm saying...
to sum it up, if you have a 92-95 civic the wiring harnesses are in two sections and they are connected by the plugs shown...you will retain the one that runs back into the firewall that connects to the ECU....


[Modified by 95hbMatt, 8:40 PM 10/21/2002]

 

Look on an obd2 harness, there are 3 plugs that you don't use in an obd2 engine harness and they are capped off under the intake manifold. I'm assuming these are the plugs you plug in, they look the same anyways.

 

alright if you are talking putting an obd1 harness on an obd2 engine. then you are gonna have to do some wiring or switching of parts.

the distributor won't plug up. the alternator won't plug up the injectors wont' plug up. but what you can do is switch the plugs from the obd2 harness to hte obd1 harness.

i have put two obd1 motors in obd2 equiped cars and i have to switch alotof plugs both times. So i am guessing that when you do the opposit you hsould have to do the same or am i wrong?

jesse

 

what were saying is that there is obd1 plugs on the obd2 harness...not the same one that the obd2 plugs though, they are tucked away under the intake manifold on obd2 motors and are not used at all. So you can use the obd1 plugs that are on the obd2 harness and you won't have to swap plugs and what not.

 

damn, seeing that makes me want to get a 5th gen. hatch. so say i was to get a 5th gen. hatch and put a 98 jdm/usdm itr motor in it using a chipped p28 ecu, would i be able to use a 96-98 ex wiring harness on it and plug it up the way the picture shows it or do i have to do as the pic. says and use a obd II si or gsr harness? damn, this sounds interesting.


[Modified by star&buc, 2:15 AM 10/22/2002]

 

 

Yes, 95hbMatt you completely understand what we're talking about. I'll try and explain one last time for everyone.
I have a 92 VX hatch and it is OBDI. I yanked out the motor and ECU and I bought a 99 B18C1 and it is OBDII to drop in. Now my swap came with everything including the engine harness that wasn't cut so I was able to use it. Now since the motor is OBDII, so are all the parts on the motor - distributor, injectors, etc. I bought a P72 OBDI ECU which plugs into the ECU connectors under my dash. I bolted the complete OBDII motor into the car and plugged the OBDII harness into the plugs on the shock tower (the ones circled in the pic above).
So what I have now is a complete OBDII setup running on an OBDI ECU so technically it's OBDI. You can only do this in the 92-95 Civic's or 94-95 Integra's. The 96+ Civic's have a one piece engine harness that goes from the motor directly to the ECU. The 96+ Integra's still have the 2 piece but they are already OBDII so they can be kept completely OBDII including the ECU if you swap.

There's nothing else to explain really. Go have a or a and if you can't understand have a

 

i just want to know if this will work on a 5th gen. hatch using a jdm itr motor with usdm 96+ integra engine harness? i know i'll need a chipped p28, etc.

 

Yea...I get it. When thinking in terms of a civics engine harness that is when I get all messed up.

 

doesnt the 99 civic si go straight to the ecu without any intermidate plugs on the shock tower????? i know the gsr harness connect at the shock tower but i think the si one runs straight to the ecu......

 

This is true....kinda throws a wrench in my thinking now.....pic says 99 Si will work....

 

sooo what the hell am i supposed to use a gsr one? and if sooo what plugs go where since there are a few extra...

 

i believe it said up top that some of the plugs will not be used.

 

you can't use the 99+ si harness. and it's only the 96-98 integra harnesses that will work with this.

also, you're going to have to switch around or add some wires if you use the obd2 harness.


[Modified by ahcjar103, 5:22 AM 10/23/2002]

 

Correct. The 99-00 Si is just like the 96-00 Civic's and is one piece from engine to ECU.

Wrong. You can add 99 Integra harness to your list because I used the 99 GSR harness in my 92 VX.

Wrong. Like I said my motor is a 100% complete 99 GSR OBDII. I didn't switch around any wires and only one plug was left that never plugged in at the shock tower. The only wiring that I had to do was the knock sensor, secondary butterflies and convert to the 4 wire O2 sensor which is normal with any year GSR swap in a VX.

 

Let me explain my swap.

93 SI hatch.
98 JDM ITR Motor.
Plugged the the harness in that came with the motor to the chassis harness.
Swapped vtec solenoids out (if you have a USDM motor this isn't required)
Got my P28 rechipped to run this motor and had no hassles

 

98 b18c1
95 LS
OBD1 wiring harness
p72
no cel.

Tom

 

oh yeah, does connecting the harness there work for the hatches that don't come with vtec wires. meaning will vtec still engage on the hatches that don't come with vtec wires.