D16Y7 to Y8 complete swap - help required

**mr_nick** · 22-08-2011 08:04 AM

Hey guys, need some help...Tried searching the sticky's but couldn't find what I was looking for. 'ecuman' has helped me out a lot so far regarding the immobiliser bypass, but I'm now stuck...details below:

Car is a 99 civic coupe ls, originally running a Y7, with OBD2B ecu & loom.

Donor Y8 engine, loom & ecu came from a 97/98 sri (I believe). Loom & ecu are OBD2A.

The Y8 engine & 2A loom are both fitted, however...Part of the 2B loom seems to be incorporated with the interior loom, it also seems to control the fuel pump relay, so I'm left with this:

...an extra ecu plug and a car that wont start. Thought originally it was the immobiliser in the 2A ecu, which has since been bypassed, but still no sign of life from the fuel pump (which I now know is down to the loom).

What are my options?

-Take it all out and just do a mini-me swap?
-Convert it all to obd1?
-Is it possible to convert 2B to 2A?
-How do I incorporate the extra ecu plug?
-What loom/ecu combo do I need to run to keep the Y8 and run vtec?
-Other...lol

Obviously I'm looking for the least time/money consuming option but either way I need to get back on the road, just don't know what to do next...

Any help or input would e greatly appreciated guys!
Thanks,
Nick

**ECU-MAN** · 22-08-2011 04:52 PM

Hi Nick

I will stop helping you via PM and add info here as it may help someone else one day

first of all I was not aware your old ECU was OBDIIB, this is infact the reason for that lonely ECU A connector on the cabin loom.

- you should be able to plug your ECU into the 3 connectors that come from the engine loom ( right 3 ECU Connectors ).
- you can ingnore the lonely ECU A connector. If it bothers you that it is there, then you can cut it off and post it to me

- all you have to do is get the wiring right at the green connector. You have to figure out what goes where and move wires across to make it all match up. I have no data for you to post up to help you, but I can figure it out from your old engine loom ( OBDIIb ) and an OBDIIa engine loom I think I have. You dont have to cut any wires but simply remove them from the connector and put them in the correct place.

the above would be your cheapest and quickest option.

**mr_nick** · 22-08-2011 06:41 PM

Originally Posted by ECU-MAN

Hi Nick

I will stop helping you via PM and add info here as it may help someone else one day

first of all I was not aware your old ECU was OBDIIB, this is infact the reason for that lonely ECU A connector on the cabin loom.

- you should be able to plug your ECU into the 3 connectors that come from the engine loom ( right 3 ECU Connectors ).
- you can ingnore the lonely ECU A connector. If it bothers you that it is there, then you can cut it off and post it to me

- all you have to do is get the wiring right at the green connector. You have to figure out what goes where and move wires across to make it all match up. I have no data for you to post up to help you, but I can figure it out from your old engine loom ( OBDIIb ) and an OBDIIa engine loom I think I have. You dont have to cut any wires but simply remove them from the connector and put them in the correct place.

the above would be your cheapest and quickest option.

Excellent John thanks very much for that! So I just need to find the wiring diagrams for each of the green connectors and pair them up? That's a relief!

Thanks!
Nick

**steve spedd** · 20-02-2012 05:13 AM

Nick/John,

I'm from the UK and am currently at the same situation that you were on the post above. I have a Civic Coupe which had the D16Y7 engine in and i have put the D16Y8 engine and loom in. I have the ECU which matches the engine and loom. I have turned the ignition and lights come on (no immobiliser or engine warning light) and the fuel pump doesnt prime. I presume this is because of the same problem as you were having. Did you manage to resolve? i have looked and there appears to be about 4/5 wires that dont match up. Are these not required? Any help welcome.....

(sorry this is my first post, i was on google and it brought me to this fantastic forum)

Steve

**ECU-MAN** · 20-02-2012 06:20 PM

Hi Steve

welcome to OzHonda

well the same advice then applies to you as well. You would have to identify what the exsisting wires do on the green cabin connector then the green engine connector and match the wires up.

you will have an immo missmatch and you will not be able to program it up since they are different immo generations. You will have to disable then immo in you ECU, you can find how to do this in a DIY I made here. search the DIY section.

- you should be able to plug your ECU into the 3 connectors that come from the engine loom ( right 3 ECU Connectors ).
- you can ingnore the lonely ECU A connector. If it bothers you that it is there, then you can cut it off and post it to me

- all you have to do is get the wiring right at the green connector. You have to figure out what goes where and move wires across to make it all match up. I have no data for you to post up to help you, but I can figure it out from your old engine loom ( OBDIIb ) and an OBDIIa engine loom I think I have. You dont have to cut any wires but simply remove them from the connector and put them in the correct place.

**steve spedd** · 22-02-2012 12:07 AM

Thanks John.

The problem i'm having is that i cant find any Data on the Main Dash loom. The colours on that are completly different to the engine harness. I have found loads of information on the engine loom (see attached) the engine is a D16Y8 from a 1997 civic coupe and the car is a 2000 civic coupe which was running a D16y7. Also attached is the colours i have. Any ideas which wires mate up with the engine loom?

**steve spedd** · 22-02-2012 12:08 AM

on the hand drawn sketch the top image is what the engine loom has and the bottom one is the one to the dash loom...

**steve spedd** · 22-02-2012 06:04 AM

just noticed that the attachments didnt work. I'll try again....

**steve spedd** · 22-02-2012 06:33 AM

Cant do that until tom when im in the office. What i need to know what on the second page what each wire actually does ('99-00 model)... for example 21 is RED/YEL (PGM-FI) -what does that actually control? I thought it was the starter signal switch (as per the hand sketch above) but i cant find out what they are. Any ideas John?

(PLEASSSSSE)

**ECU-MAN** · 22-02-2012 08:03 AM

ill check my data for the green connector on a OBDIIa looom and you may be able to use that to marry everything up.

Give me some time to check it all out

thanks for postaing the info you have

can you confirm the "Green dash loom" diagram is pin view or wire side view of the connector ?

**ECU-MAN** · 22-02-2012 08:17 AM

Iv had a look at my P2K Loom Data and can confirm your " Exactly as Car " diagram is correct.

the unknown is what your " Green Dash Loom" info is. I have an OBDIIb engine loom, this weekend I will find it and perform a continuity test on the green connector to identify the wires on the Green connector to the rest of the loom to help identify the pins. This should work. Unfortuanatly I cant do it any sooner. If you in a big rush to sort it out, perhaps you can do the same to your OBDIIb engine loom and post the info here.

**steve spedd** · 22-02-2012 08:19 AM

Hi John,

thanks for getting back to me...

its pin view. I have found this in an attempt to find out what the PGM-FI mean: http://www.justanswer.com/uploads/Ho...001943_inj.pdf

but not sure if that right. I seem to have a conflict with the VSS and the STS. Well as loads of others!

from what i can see pins 1-5 and 11-17 do nothing on the manual Y6 c131 connector. these are mainly for Auto trans and the engine imobb.

If i dont do the immob ecu mod as you show (thanks BTW) in the DIY section will the car not start at all? is that something i need to do first?

sorry for all the questions!