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obd2a to obd1

Posted: Mon Jan 25, 2010 6:57 pm
by CarteluL
i have a problem guy`s...i made all the convesrion to obd1 from dodo-upgrades.nl but in the finish i have 2 wire`s with igp2 and 2 wire`s with sg2...i konw i sould split them ...but how ? add together those 2 igp2 and sg2 wire`s and pin them in the obd1 ecu ?

Re: obd2a to obd1

Posted: Mon Jan 25, 2010 9:14 pm
by Dodo Bizar
Ah we sorted this out on PM.

The SG2 (and IGP2) towards the ECU is fine. But you need to hook up the heated lambda IGP2 and SG2 wires (and VTEC ground). This is done by several splits from the SG2 and IGP2 wires going to the ECU.

Re: obd2a to obd1

Posted: Tue Jan 26, 2010 7:55 pm
by hondaNickx
I just noticed this and to my suprise i didn't even knew this .I think i actually never thought about it.But if i'm right the D14 allready uses 2 IGP's ( IGP1 and IGP2) and 2 SG's (SG1 and SG2 ), so you need to hook up a 3th for the 4wire lambda by splitting the sg2 wire ?That would make that actually SG3 and IGP3.And that would make sence to me since igp2 and sg2 are allready there in the D14 engine harness.It got me confused here for a while too ...

Re: obd2a to obd1

Posted: Fri Jan 29, 2010 9:50 pm
by Dodo Bizar
No its different.

There are 2 seperately monitored circuits, the 1 and the 2.

The no. 1 circuit, is solely the MAP circuit which is the most important sensor for the ECU. If that one fails, engine certainly will perform less. Therefore its seperated.

The no. 2 circuit is all the rest. Inside the EJ9 wireloom, under the IM is a big splitter, plug. In here several circuits are split into multiple wires, I think IGP2, some grounds are there, but also SG2 is split there. Its used for at least TPS and IAT, probably ECT as well. I recently puzzled this out for 'Goofy' his car which had many wiring problems. I cleaned is loom and in the process needed to pass this splitter plug were I noted the above.

So when having a heated lambda, I am 90% certain the splitter will have one additional split for it which misses in our EJ9 looms.

Btw in older generations I've heard (never cleaned older looms), that the splits are made as well by Honda, but they are hidden in the loom. This makes some sense since even in the EJ9 loom some 'old skool' splits are to be found at locations were ground protection starts (ignition wires, lambda signal wire).

Re: obd2a to obd1

Posted: Fri Jan 29, 2010 9:53 pm
by Dodo Bizar
Strictly speaking, this is also the reason you should not mix up SG1 and SG2 etc. etc. since faulthy error codes could arise from it. Never noticed it, but better be safe than sorry.

Re: obd2a to obd1

Posted: Fri Jan 29, 2010 10:28 pm
by hondaNickx
Weird :s i can't even remember how i did it ,i think i took a split of the SG2 wire before the ecu .I never even looked into that splitter box you mentioned.This should be something that needs to be noted in the obd1 swap article makes it that much easier for people to understand.

Re: obd2a to obd1

Posted: Sat Jan 30, 2010 7:50 am
by Dodo Bizar
Point taken, I'll put it in the eh... workshop section or whatever it is called.

Re: obd2a to obd1

Posted: Wed Feb 03, 2010 9:25 pm
by CarteluL
Ok guy's..i did it..but..nothing..it don't wan't to start..i studied all the loom and it's fine..after that i read that i must to degree the camshaft to 16..here's the big problem..on my crank pulley i have only one mark..the OEM mark..wtf? Can i use the d16z6 crank puley because next month i wan't to install a z6 head..any pic's would be VERY HELPFULL..10x

Re: obd2a to obd1

Posted: Thu Feb 04, 2010 2:19 am
by CarteluL
I looked more carefull and i found the 4 marks..and i have another question..first when i just make the obd1 swap i must to degree the timing to 16'' (crank pulley) and the head must be at 3-9 point's wright? And after the head swap i must to put the crank pulley to TDC (OEM timing) and the head pulley at 7o'clock ? I now i ask allot of 'noobish' qustion's but i don't want to brake something..chear's

Re: obd2a to obd1

Posted: Thu Feb 04, 2010 2:35 pm
by mynameisowen
CarteluL wrote: I now i ask allot of 'noobish' qustion's but i don't want to brake something..chear's
Dude thats what we are all here for man :D keep them coming, these sort of topics will help anyone in the future with the same problems.