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Discussion Starter #1
ok so i have a great running d16y7. i want to swap intake manifolds to the manual y8 so i offcourse have to change the iacv to a two wire. i also want to convert it to obd1 using a ecu jumper with a p06 ecu.
*i want to keep the car non vtec
*when i swap to obd1 i do not want to loose my AC
*i just need to know any more info or tips before i start this, so i dont run into and problems or snags.

oh yea im also building a turbo kit for spring but i need to go to obd1 before i do anthing else....
 

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99 Hatch
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It will work fine. As long as you wire the IACV right everything should be ok when tuned. You can always just use the IACV on the Y7 TB, thats what I did and its fine. The only thing I'm unsure of is AC, I have a CX so no AC for me.

The only thing I did when I did mine was change the ECU to a P06 and run a OBD2B-OBD1 harness. I kept my Y7 TB and 3 wire IACV
 

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Discussion Starter #5
so i just want to run the car on a obd1 for the winter and when spring comes i will boost it. do i need a tune just to run it all stock. the only mod that is done to it is apexi ws2 exhaust.
also is there anyone that knows that if i convert to obd1 if i can keep my AC??
 

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It will work fine. As long as you wire the IACV right everything should be ok when tuned. You can always just use the IACV on the Y7 TB, thats what I did and its fine. The only thing I'm unsure of is AC, I have a CX so no AC for me.

The only thing I did when I did mine was change the ECU to a P06 and run a OBD2B-OBD1 harness. I kept my Y7 TB and 3 wire IACV
thats what i want to do as well but people kept telling me that i would have to do the iac 2 wire conversion on the y8 intake manifold. i have a y8 intake manifold but its from an automatic with no iac. i am using y7 tb and iac

i want to go obdI so i can tune it
 

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99 Hatch
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thats what i want to do as well but people kept telling me that i would have to do the iac 2 wire conversion on the y8 intake manifold. i have a y8 intake manifold but its from an automatic with no iac. i am using y7 tb and iac

i want to go obdI so i can tune it
Humm, well don't do it yet. I'm having problems with my IACV but I don't know if its the wiring or if it just took a crap on me. I'm only driving my car in the summer so I may just tune out the IACV.
 

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68 Camaro
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im half temped to block off the iacv on my when i do my y8 swap and just set up an idle screw...
 

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not tryin 2 highjack ya thread but i have sort of the same question...i have a 96 civic 0bd2 and i swaped a d16z6... and i was wondering my cars not starting..so im guessin its the comp??? rite ??? if yes will it work whit an p2p...?or would i have 2 do a step down... 2 like a p28.... is it a must??
 

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Discussion Starter #10
bumb.
i am almost ready to do this swap. have everything just a couple more questions
*when converting to obd1 do i need to set my timing 14 degrees btdc or is this a myth?
*am i able to keep ac when going to obd1? i removed the po6 out of a 1992 eg with ac,ps and it was a 5speed..
 

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96 hatch SIR
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Simplest thing to do is to get a y8 manual mani convert your 3 wire clip to 2 wire clip and repin it at the ecu (convert 3 wire to 2 wire) get your pig tail use your po6 ecu and be done. AC is totally something else from your engine swap, no need to worry.
 

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98 Civic CX-T on E85
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agree with 99d15b before i took my a/c everything worked fine when i went to obd1 on my d16y7. i also ended up doing the iacv conversion. its really not that hard. ff squad has a good writeup on it. im running a chipped p06 non vtec tuned on Crome Pro and an ostrich. if you do the y8 i/m swap make sure you get the y8 tb gasket mine surged until i swapped gaskets out...
 

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Discussion Starter #14
agree with 99d15b before i took my a/c everything worked fine when i went to obd1 on my d16y7. i also ended up doing the iacv conversion. its really not that hard. ff squad has a good writeup on it. im running a chipped p06 non vtec tuned on Crome Pro and an ostrich. if you do the y8 i/m swap make sure you get the y8 tb gasket mine surged until i swapped gaskets out...
ok thanks.yea i did buy a y8 intake manifold gasket threw the honda dealer. i replaced all the gaskets and hoses with oem honda so i know they are good. i also replaced the pcv valve cause they are diffrent. thanks for all the help
 

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obd1 ecus only use 2 wire iac valves. One wire has power and the other is controlled by the ecu and pulses the ground. The iac has a spring that closes the iac when the ecu is not supplying a ground 100% closed

The 3 wire is different It has a neutral position (50% closed) a hot and the ecu pulses 2 wires one to open one to close (reverses polarity on the iac motor). The idea is if the iac fails it will go into neutral position and be slightly open where as the old style 2 wire will just close. Causing problems like killing the car at idle. The ob1 ecu dose not have the hard wear or the programming to run a 3 wire iac only a obd2 ecu will...........

As far as the ac contact Rywire - Online Store he should know and he makes good conversion harnesses.


( I know what the next post will be “but I can unplug my iac and the engine will not kill out on me” you have your air bleed screw seat correct or set high. The 3 wire is more of a fail safe design. If you air bleed was clogged or set wrong it would kill……… )
 

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2001 TL1000R
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SO i just found this thread- i have a 97 civic with a y7 and y8 mani, blocked of the iavc and used the y7 throttle body- its been running great ever since i got her together, i JUST Today put in a chipped base map p75 obd1 ecu in and it went surge haywire! i left it idol (surge) and went under the hood to unhook the iavc(figuring that may be my problem for whatever reason) it then stopped surging but the idle was stuck between 2,500 rpm and 3k (tried it twice and those two rpms where my result) ANY SUGESTIONS??:(
 

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2001 TL1000R
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So by searching and trial and error i found out it was due to the y7's IACV being 3 wire- i don't really know if you can just bypass it but tomorrow i will be switching it over to 2 wire and doing the repining of the ecu harness. hopefully it will be a success because i tried hooking back up the obd1 ecu with the IACV completely unhooked and it ran fine(other than idle being 1,500 rpm but it was pretty steady without alot of surge) i prob. shouldnt be answering my own questions but maybe it'll help another n00b on here~
 

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Civic Aerodeck
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Just found that you can disable IACV in Crome free,it's in the plugins, gonna try it tomorrow as I have similar problems to you.
 

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1990 integra
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i did a obd1 z6 intake manni swap on my obd2b y7 and the only thing i had to do was extend my MAP sensor and re-run coolant lines and mine is running GREAT and im still using the stock obd2b y7 computer....and it completly got rid of my surging problem and the MAP and IACV plugged right up....IMO id try a z6 IM instead of the y8...
 
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