I have a 90 std hatch with b1 in it.
I also have a complete b7 engine minus the wire harness and tranny sitting in the garage.
What parts would I need to build my b7 engine into an a6 and keeping it obd0?
I know I need an si ecu (PM6) and I guess the the si intake with injectors.
Can I use my obd0 dizzy from my b1 on the b7 head? Or do I need an a6 head to put on my b7 block??
I need a parts list of the cheapest and easiest way to turn my b7 into an obd0 a6. Thanks!!!

 

Would it be easier just to throw the b7 into the car and just figure out the obd0 to obd1, DPFI to MPFI conversion? Cause I have the obd1 ecu, dizzy and intake/injectors that came with the b7.

 

Buy a D16a6. Thats the cheapest and easiest way. The D16a6 came in the 88-91 CRX Si and is obd-0 and Non-vtec.
I also don't understand "building a b7 into an a6?" Do you mean put all the D16a6 internals inside the D15b7? Or putting the a6 head onto the b7 block? Which would really be quite pointless.

 

Yeah I guess I mean putting an a6 head on the b7 block. But then I would need to get the ecu, dizzy, injectors and intake off he a6 too, huh?
It's just a shame cause I have a perfectly good b7 sitting around.

 

so.. i guess i already know what parts i need to build my d15b blocks into an a6???

 

i think the a6 head is like the b7 head.. so really all i need is the a6/si intake, injectors and ecu???
no one on here know whats i need for this?
the only answer i get, is that i should buy another engine?

 

I wouldn't bother trying to put any A6 anything on that B7.
They both produce nearly the same power.

Since you have the B7, I would put that in as is.
Do a the DPFI to MFPI conversion.
Get a P06 ECU and an OBD0-to-OBD1 harness and call it a day.

 

I'll try to clarify things a bit more simply here...

88-95 1.5 16 valve non -VTEC engines are basically the same. The difference will come from the camshaft.

88-95 D-series non-VTEC 16 valve heads are essentially the same thing minus valve spring differences from the 1.6 A6 variants.

That being said, your B1 is essentially a B7 with a different camshaft. Swapping parts is like removing it just to replace it with the same thing. The main difference of the A6 is MPFI and displacement. You can convert to MPFI but you can't swap parts to match displacement without using a 1.6 block to begin with.

If the B7 is a physically "healthier" engine compared to your B1 then go for the full swap. I'm with "4drEF" on this one. Considering you have the ECU, distributor, and manifold with injectors for the B7 I'd do exactly what he said (if it were me anyway).

If there's nothing wrong with your B1, then I'd leave the block/head in there and swap the manifold/dizzy/ECU/camshaft and complete the DPFI>MPFI conversion along with the jumper harness to use the ECU for the B7.

 

Yeah, I heard that guys. Thanks. I'm just gonna have to bite the bullet and do the obd0 to obd1 route. At least I'll be obd1 for any future b series swaps..
It just sucks cause I bought the entire b7 set up for $150 and just the wiring harnesses alone are gonna cost me more than that. That's some funny ****.

 

Waring harness will not cost you more than that.
Use your stock harness and convert it to fit the new engine.
(FREE)

Jumper harness is like $100.
Contact this guy "crx_si-r"
https://honda-tech.com/forums/members/crx_si-r-999500162/
He had a good business making great harnesses for a great price.

 

I was gonna try and get my hands on an uncut obd1 harness and just cut the pigtail connectors i need off of it and splice them onto my obd0 harness where nessecary. Same thing for the cabin....
Has anyone ever hard wired through the chassis to the cabin? Not using any pigtails.. Just wire??

 

That is possible.

Good - stick to the plan of converting your stock engine harness with plugs from the OBD1 harness.
You actually won't need many of them at all.

The ECU plugs connectors can be hacked off and wired up.
It's how we used to do back in the day before jumper harnesses.
There are diagrams all over for how to wire it.
Quick search got me this... I don't feel like looking anymore for better ones so good luck!
There are better BTW - this one doesn't have wire color for OBD1.
http://www.b20vtec.com/forums/ecu-tu...n-diagram.html

I suggest you stay away from any consideration to use the complete OBD1 engine harness.
Just omit the idea from your head if it ever comes up.
Firewall connector will have you pulling off your dash and remove the dash harness for modification.
A lot of the wires will need to be routed to the opposite side of the engine bay to meet up with the proper engine harness locations.
I have actually done this working solely from Helms schematics.
LOTS of wire probing and continuity checks.
Totally not worth the effort.

 

I have a simple solution, find a obdo wiring harness, a 91 si engine and trans and put it in. Unless you are very well versed or an electrical engineer, a lot of time and energy will be wasted. I personally wouldn't waste my time or energy cutting up a perfectly good, nice car to do this.
dave
"time wounds all heals"

 

Thanks 4drEF. I'm gonna totally do it. I do hvac maintenance for a living so I'm not affraid of schematics or a lil' wiring. I think I can figure it out. They seem a lot alike, just got to ad some wires for the injectors, the fan switch and other things here and there. Should be exciting to say the least. Thanks everyone for their help.

 

so i cut out most of what i can get from a 94 civic dx hatch engine harness and i cut the p06 ecu out leaving as much wire as possible to do the splicing to my obd0 wires coming in from the fire wall in my car.

i think i can google search the obd1 pin outs and cross reference them with a google searched, obd0 pinout.. is there anything i should keep an eye out for? am i gonna have to pull wire through the firewall directly to the ecu for injectors or anything?

when it comes to the engine harness.. what pigtail connections do i have to cut off my obd1 harness and connect to my obd0 harness?
i know the dizzy connections are different... but what else? don't i have to ad some wire for a coolant sensor or something?
also i have an std model civic, so i'm pretty sure i dont have a resistor box.. plus im gonna be using obd1 injectors, so i don't need a resisitor box.
i see a lot of "dpfi to mpfi write ups" are for 88-91 si harness conversion where the resistor box is included. since i dont have all that ****, shouldn't my injector wiring be relatively easy? i think i just connect like 4 yellow wires to a red wire?? can someone confirm this for me? thanks.

is there anything else i need to know? i think i have to swap out the drivers side engine mount on the b7 motor for my stock 88-91 engine mount.

 

The DPFI-to-MPFI write-ups do not use an Si harness.
They convert the DPFI to MPFI - adds a couple wires to support the 2 additional injectors.

On the OBD0 ECUs -
> The the STD and Si have different spots for the Crank Angle Sensor (distributor) 2 wires at the ECU plug (C1 and C2) are moved to new locations (B10 and B12)
> The C1 and C2 locations are now empty, however the MPFI uses them for the cylinder positions sensor. If you were staying OBD0 you would need 2 ECU pins with pigtails. 2 New wires are added and pulled out through the firewall.
The outer wires on the TPS connector are reversed.

So, a total of 4 new wires through the firewall.

Right off the bat, you will need the distributor plugs off the B7 harness.


It would appear that you are going to use the STD engine harness and convert your ECU plugs to OBD1?
Just making sure I am reading your intent correctly.

Put your STD harness on the new engine and hook up all the connectors.
It will become apparent for what needs to happen.
It may be of some help to label your STD harness before disconnecting from the engine.
Label all the connectors for what they plug into so when you hook up on the new engine, you don't get them confused. Some of the connections use the SAME connector style.

Since you are not going to use the resistor box, you take one wire (the red ones) from each injector and solder them all to the heavy wire (yellow) that supply power from the main relay.
The other wires on the injectors supply the ground pulses from the ECU.

You will need to reuse the engine mount bracket (the part that bolts to the block) from your STD motor.
This may require a little trimming to the B7 belt cover.

Take a look at the thermostat housings on both motors.
The B7 has a sensor in it which is the temp control switch for the radiator fan.
The STD has this switch mounted on the back of the block near the oil filter - it is the green one with the two prongs.
You will have to extend the wires from the STD location and wire in the connector for the B7 switch.

 

im not going to stay obd0. i want to go OBD1. so what wires do i need to add for that?

thanks a lot man, i have some wiring diagrams, but they're not really color coded. im finding more si info than std.

 

You still need to add and move the wires for the DPFI to MPFI.
It MUST be done.

The link I sent in a previous post goes pin-to-pin for OBD0 to OBD1.
I don't think you will find any for STD/DX since you have to add and move wires to convert.
The color coding would not 100% apply.
However, once you bring your STD wiring up to MPFI spec, then all the wires will be in the proper locations to match pin-to-pin for the conversion.

Stock wire colors for your OBD0
http://hondaswap.com/reference-mater...67/#post429416
Again - these wiring colors will not apply once you add wires for the 2 new injectors, move C1 and C2 to B10 and B12, and add new wires for C1 and C2.

 

yeah, but i'm going to cut my obd0 ecu connectors off. (leaving me about 50 colored wires dangling at the passenger cabin wall) and i plan to splice (the dangling 50 obd0 wires) to my already cut obd1 ecu harness wires.
i'm gonna most definitely use the info you have given me, to mark the obd0 wires before i cut them from their connections.. but if i do this. do i really need to repin C1/C2 to B10/B12?
can't i just splice the C1/C2 wires to the corresponding obd1 wires? and then just add the cylinder position and tps wires to the newly molested obd1 wire harness?

and about the added injector wires, they don't get pulled through the firewall and added to the obd1 ecu harness, do they?

hey 4drEF, i appreciate you helping me out man. i'm trying to sift through all the info you've given me and figure this **** out. it's a little overwhelming at the moment. i'm glad you've taken your time to break it down for me. thanks.

 

check out your wire colors and compare to the DPFI OBD0 wire colors I linked to.
Everything -should- be correct.

When you hack off the OBD0 (dpfi) connectors, C1 (orange) and C2 (white 4) will go to B11 and B12 on the OBD1 plug. These are the correct locations for the CYP sensor.

NEW wires you will need to pull through the firewall will be:
2 wire for injectors
2 wires for cylinder position sensor
O2 sensor heater

TPS wires already exist. You just need to flip the outer wires at the TPS connector.
Or maybe flip the wires right at the ECU (OBD1 D20 and D22)

Take a GOOD look at the colors of the ECU wires.
Many of them are the SAME color.
I strongly suggest you ether label ALL of them or simply cut/solder them one at a time.

 

Lemme get this straight. Obd0, C1 (orange) goes to b10 or b11?
Cause you said b10 in one post and b11 in another.
Thanks man!

Hey I just looked at my obd1 schematics and I think it's B11 that C1 goes to. Those are the CYP sensors.

And because I'm not using the obd0 connections. I'll just run my two new cylinder position sensor wires to b15 (blu/grn) and b16 (blu/yel) on my obd1 harness.. Does that sound like I'm starting to make sense?

 

(DPFI) C1 moves to (OBD1) B11.
C2 moves to B12.

 

on OBD1:
B10 is the speed sensor.
B11 is CYP-P
B12 is CYP-M
on OBD0:
B16 is the speed sensor
C1 is crank angle sensor
C2 is crank angle sensor

so shouldnt:
B16 go to B10
C1 go to B11
C2 go to B12

also i'm confused on the (obd1, D20/D22) TPS sensor flip-flop.
if i'm reading these schematics correctly, i would assume:
OBD1 / OBD0
D19 (yel/wht) map 5v / C15 (yel/red) map sensor
D20 (yel/blu) tps 5v / C13 (yel/wht) tps sensor
D21 (grn/wht) map grnd / C14 (grn/wht1) map sensor
D22 (grn/wht) tps grn / C12 (grn/wht2) tps sensor

on an obd1 to obd0(si) conversion chart it says:
d19 to c13
d20 to c15
d21 to c14
d22 to c12
but then you said flip flop the tps sensors on d20 and d22 (for dpfi) so it should be:
d19 to c13
d20 to c12?
d21 to c14
d22 to c15?

i'm thinking you're suppose to flip-flop d19 and d20, but what do you think 4drEF? thanks man!

 

On DPFI OBD0 (your car);
C1 is CYP-P
C2 is CYP-M

On MPFI OBD0;
C1 is CKP-P
C2 is CKP-M

B10 is CYP-P
B12 is CYP-M

You are correct on the positions of B16, C1, and C2 when converting from DPFI to OBD1 .
Now I need to go back and UNedit my previous post.
I had it right the first time.


The TPS on the DPFI throttle body rotates the opposite direction than all of the other motors.
This is why you flip the wires.
It is more straight forward to just flip them at the TPS connector and not deal with the pins at the ECU, but that is entirely up to you.

 

This chart
http://www.b20vtec.com/forums/ecu-tu...n-diagram.html
agrees with
I'm not sure where you got this?
DPFI to OBD1 should be
d19 to c15
d20 to c12
d21 to c14
d22 to c13