dubniK

Hey all. Need some help here.

Car: 1997 Civic DX
Engine/Tranny/Swap: 1998 D16y8 5SPD
**Engine harness used was off of a AUTO D16y8

I am getting codes 14, 41, 65, 91. The car runs, but bogs down hard when the gas is left off, and jerks very hard at close to idle. Code 14 relates to the Idle Control System Malfunction, but I don't know where to start. Someone help thanks!!

((41 and 65 are o2 related, and 91 is related to fuel tank pressure)


Modified by slow ek at 6:41 PM 5/25/2004

fast+forward

here's how to fix the iacv https://honda-tech.com/zerothread?id=815749

dubniK

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by breakaway &raquo;</TD></TR><TR><TD CLASS="quote">here's how to fix the iacv https://honda-tech.com/zerothread?id=815749</TD></TR></TABLE>

Thanks for the suggestion. I tried that, but my ECU pinouts are completely different. I don't even know where to start??

EE_Chris

Since you've gone from a 3-wire IACV to a 2-wire, have you performed the needed modifications to the IACV connector and the ECU pins?

What year ECU are you using? Its possible that the ECU your using is looking for a fuel tank pressure sensor which your 97 Dx might not have.....have to check the Helms for this info.

Codes 41 and 65 refer to the O2 heaters: Are yours plugged in? Do you have a multimeter to check their resistances?

dubniK

I have not performed the IACV modif. or the pinout because I can't find a chart that labels exactly what I have to do. The link posted previously looks nothing like mine on the ECU. I am running a 98 EX ECU also, with the Automatic EX wiring harness off of the same year.

EE_Chris

EK wiring information

fishnfst

Thanks EE_Chris..

So basically here's what Info I've gathered on the IACV issue:

- you need to know what type of IACV your using and what engine harness you will ultimitely use w/your engine swap, whether you own a 96-98 or 99-00 EK civic.

- All 96-00 5-SPEED VTEC models (5-speed is the key here) mainly 96+ EX coupe & 99+ Si coupe and HX/D16Y5 engine, uses a 2-pin IACV, which explains the reason why you don't have to do this IACV fix if you wind up using an Si coupe or EX engine or HX (5-speed/MT) engine harness for your B-series engine swap.

Here's the slight tricky part...
IACV's & engine harnesses from a A/T (auto) D16Y5, ALL (AT & MT) D16Y7's, and AUTO D16Y8/EX engines all use the 3-wire style IACV. So, if you plan to use an engine harness from any of these, you will have to perform the IACV ecu pinout fix and plug change.

Now that pinout fix is this...
At the ecu plug 'B', move pin B6 (black/blue wire) to B23 (should be an open pinout). B15 is the 3rd wire and is not needed anymore; so un-pin it and leave it hanging, tape it up or whatever, just get it out of the B15 pinout location.
The ecu pinout fix is done.

(I'm using a Y7 engine harness for an example)

Now, you need to fix the actual IACV plug thats on your Y7 engine harness. Remember its a 3-wire plug (will have pictures of this plug soon); we don't want that plug because it's not compatible with a 2-wire IACV which is on the B-series intake manifold. If your B-series engine has a wire harness on it, cut off the IACV plug from the harness, match up the wire colors then cut+splice it or repin it to the Y7 harness, but DO NOT re-use the ORANGE wire. Leave it hanging or whatever you wanna do with it...that orange wire is bad and unneeded.
The IACV plug fix is done.

For shitz n' giggles..
I was wondering if a 3-wire/Y7 IACV would fit on a B-series intake manifold, I hear it doesn't, but if it did, you wouldn't have to perform the second portion of the procedure above (IACV plug fix), you'd only perform the ecu pinout swap.

...that's about it for the IACV fix.

As a conclusive reminder....
you do not have to perform any of this IACV mod'ing if you use a 5-speed EX, HX, or Si coupe engine harness in your EK; nor do you have to wire any vtec components

Courtesy of KATMAN

fishnfst

Your d16y8 uses a 2 wire iacv but the auto harness is setup for a 3 wire iacv just like your y7 was. You have to convert the harness to recognize a 2 wire iacv. I don't know if the fix is the same as using a y7 harness and a y8 iacv and throttle body. If you search I posted a quesiton about this a couple of weeks ago and somone posted the pics of the fix. I did it this weekend and my iacv code is gone now. I hope you don't have to buy those damned o2 sensors they are a grip and they don't last very long. The heaters in them are always going out.

dubniK

thanks for all the help guys. just for clarification.. i have a d16y8 swap WITH a d16y8 automatic harness. i have tried the iacv fix, and going by the pics he had for my applications, it was all actually in the A plug. after moving the pin over, and splicing the correct wires for the IACV, i am still getting the same results. i am very curious however because my harness already had a 2 wire IACV plugged in, which was a BLACK and a GREEN wire, which are now left dangling. anyone?

EE_Chris

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by slow ek &raquo;</TD></TR><TR><TD CLASS="quote">i am very curious however because my harness already had a 2 wire IACV plugged in, which was a BLACK and a GREEN wire, which are now left dangling. anyone?</TD></TR></TABLE>

What do you mean it already had the 2-wire IACV plugged in? We've given you wire colors for both OBD2A and B IACV's and they are not green or black....so obviously you're using the wrong plug (sounds like power steering plug). And when you say 'splice the correct wires', you mean grafting the 2-wire connector onto the 3-wire harness?

Also note: ECU's and IACV's are specific to one another, meaning that an ECU that controls a 3-wire IACV will never control a 2-wire IACV and vice-versa.

Katman

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by EE_Chris &raquo;</TD></TR><TR><TD CLASS="quote">
Also note: ECU's and IACV's are specific to one another, meaning that an ECU that controls a 3-wire IACV will never control a 2-wire IACV and vice-versa.</TD></TR></TABLE>


...exactamundo!

what specific ecu are you using, slow ek?

dubniK

Problem solved. Thanks for everyone who chimed in. Just for the recap, I swapped in a 98 D16y8 5spd, into my 97 civic dx 5spd, but was given a wiring harness out of an AUTOMATIC d16y8.

When I first saw Katman's posts, I found that I was left with an "extra" 3 wire plug, exactly as he had pictured. However, I already had a direct 2 wire plug into my existing IACV (green/black). After fiddling around today, I found that my old D16y8 manifold had another sensor on the bottom of the TB attached to it, as mine DID NOT? SO....I re-pinned the ECU back to the original setup, moved the 2 GREEN/BLACK wires back to the IACV, and swapped the TBs off of the two manifolds, and then plugged in the lose 3 wire plug. All is well now!

THANKS EVERYONE!!!!!!!

***any idea what that plug on the bottom of the TB is?

EE_Chris

Auto Y8's used a 3-wire IACV that was mounted on the throttle body while 5-speed Y8's had the 2-wire IACV mounted on the manifold.

So are you running a 2 or 3 wire IACV?

Katman

yah and some pictures would be nice too!

I don't have any pics of the an AT Y8 manifold + TB either....wish i did

dubniK

I am aware of the Auto/5spd difference with the IACV.

But what I am saying, is that I had an AUTOMATIC harness, with the 2 Wire Plug/Harness already there, ANNNNNNNNDDD I also had the 3 wire harness/plug, that needed to be plugged into the sensor at the BOTTOM of the throttle body where the coolant lines go into. Pics should be up soon.

fishnfst

Onthe bottom of the tb or on the back? It wasn't your tps was it?

brooksto

If you got it working Im not going to say you are wrong, but this statement

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">But what I am saying, is that I had an AUTOMATIC harness, with the 2 Wire Plug/Harness already there, ANNNNNNNNDDD I also had the 3 wire harness/plug, that needed to be plugged into the sensor at the BOTTOM of the throttle body where the coolant lines go into</TD></TR></TABLE>

is incorrect, you have some plugs mixed up, the auto y8 throttle body has a 3 wire iacv on the bottom, which the auto y8 harness accomodates with a 3 wire plug. The manual y8 intake manifold has a 2 wire iacv on the back of the IM, which is accomodated by a 2 wire iacv plug on the manual harness. From what you have said, it sounds like you are using an auto ecu? If you are using an auto harness with a manual ecu, you should have 1 plug at the ecu end that hangs loose as the manual ecu only uses 3 plugs from the harness, the auto ecu uses 4.

[EDIT] and let me know if you figure out code 91, ive been trying to solve it since the auto to manual conversion, its the only code im still throwing. I think it is related to a difference in the auto and manual ecu that may be solved by repinning but have been unable to solve yet, but the fact you are throwing it also is helpful in knowing it likely isnt an evap leak like is tries to indicate.

dubniK

thanks for your input. i know exactly what you mean, and i can also picture exactly what you are trying to say; especially based on most of the threads i've found while searching for my answer. however, NONE of those threads solved my problem.

the difference in my scenario was this: my wiring harness was REMOVED from an automatic civic ex. the swap i was using was a manual 5spd D16y8. At the end, I was left with TWO questionable plugs.

1. 2 WIRE, GREEN and BLACK going from the harness into the IACV already.
2. 3 WIRE, ORANGE and Y/B and G/B (my loose plug).

per the findings in the threads, i re pinned the ecu for my application, and also re wired the 3 wire into the 2 wire. so far, it sounds like the EXACT solution needed correct? but NOT for me. same codes, same problem. (diagram used attached)

i found that for some reason, the TB that came with my swap was missing a 3 wire plug in as i later found on my previous Y8 manifold setup. I simply swapped the TBs around, wired all the plugs back to the way i received them, and re pinned the ECU back to the way it was also. and THIS, solved my problem. i've been lagging on the pictures, but it'll be a lot easier once you see them.

so to recap, the harness basically worked correctly for my application, minus having to swap out the throttle bodies. which brought me to a new question. i'm curious as to WHY they were different, whether its dependent on years or whatever. anyways, i'm just happy my car runs now.

Katman

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by slow ek &raquo;</TD></TR><TR><TD CLASS="quote">... which brought me to a new question. i'm curious as to WHY they were different, whether its dependent on years or whatever. </TD></TR></TABLE>

...who knows, go ask honda

brooksto

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">1. 2 WIRE, GREEN and BLACK going from the harness into the IACV already.
2. 3 WIRE, ORANGE and Y/B and G/B (my loose plug).</TD></TR></TABLE>

I am saying this is wrong, again, not trying to start an argument, but it could very well be the reason you are throwing the other codes. The auto harness does NOT have a 2 wire iacv plug, there are several 2 wire plugs on the harness that fit, yes I think even with green/black wires, but they go to different sensors. I think the 2 wire plug you have on the iacv right now is meant for a different sensor. From what you describe, you now have 2 iacvs hooked up, 1 on the back of the intake manifold (2 wire MT) and 1 on the bottom of the tb (3 wire AT). There is no way there was already a 2 wire iacv plug on the auto harness unless it was modified and ran seperately, because when you do an iacv conversion on the auto harness, you cut the 3 wire plug that went to the auto tb off, and solder on a 2 wire plug, and then run it to the iacv on the intake manifold, as posted on that picture. Again, if it works, Im not going to argue, but it could be the reason for some of your other codes, because after my auto to manual was done completely, I am only throwing code 91.

dubniK

are you 100% positive that what you're stating is consistent through all years of applications? again, i watched them pull the harness out of an automatic vehicle, and the swap i used was a 5spd d16y8, straight from a totalled (stock) car.

i have no additional sensors/wires that are questionable at this point, and i could not find any other 2 wire sensors similar in color/shape. i did another search recently and found that someone else ran into the same problem as myself. he too could not get the codes cleared based on the diagram listed above.

i do have a secondary o2 code flashing, but that's simply because i'm "missing" it.

ps. code 91 was cleared up by a local shop; said i had some fittings loose or whatever by the fuel filter.

brooksto

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by slow ek &raquo;</TD></TR><TR><TD CLASS="quote">ps. code 91 was cleared up by a local shop; said i had some fittings loose or whatever by the fuel filter.</TD></TR></TABLE>

Ill have to check that, I didnt add the crush washer when screwing the fuel line back down on the filter so that could be causing it.

No Im not 100% sure,especially when it comes to obd2b. But ive had 3 ob2a d16y8 auto harness and all had the 3 wire iacv plug that had to be converted to work. Again, if it works for you thats great because youve found another solution to the problem.

dubniK

again i appreciate all of your input. i will take the pictures soon and post them up so you can see. maybe judging by the pictures, you can better explain what i've been trying to say! haha.

and i just called the mechanic, and he said my upper fitting where i had my fuel pressure gauge was missing one of the crush washers, and didn't appear to be tight enough initially. hope that solves your code 91!

fishnfst

Ok kev you got it running, it must be time to yank it out and sell it.

dubniK

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by fishnfst &raquo;</TD></TR><TR><TD CLASS="quote">Ok kev you got it running, it must be time to yank it out and sell it. </TD></TR></TABLE>

LOL!!! Dude. I've been trying to decide what my next move was too! K20..or sell the car? Hmm..the car's already on craigslist..so we'll see.