I put a B-series Integra throttle body on a Y8 IM and head on a A6 block. Started up fine, idled way high, and then when it's fully warm it starting hunting up and down.

I've found that this may have something to do with a bolt? screw? that's inside a fast idle valve, but I'm not sure if my TB even has one.

Also, is it unnecessary to have my IAC on the back of the IM plugged in? Somebody else suggested I unplug it . . .

 

OK, the suggestion to unplug the IAC was about setting the idle screw - not a suggestion to unplug it permanently.

Any help out there?

 

Does the Y8 IM even have holes for the IACV ? I know u said IAC, but do u mean IACV? From what i remember, Y8 IM's have the IACV on the throttle body, and they have a 3 wire connection instead of a 2 wire. The FIV i believe is on the B series throttle body right? On my B series i just plugged the vacuum port for it inside the TB. Hope that made sense to u.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by fourthgenhatchB17 &raquo;</TD></TR><TR><TD CLASS="quote">Does the Y8 IM even have holes for the IACV ? I know u said IAC, but do u mean IACV? From what i remember, Y8 IM's have the IACV on the throttle body, and they have a 3 wire connection instead of a 2 wire. The FIV i believe is on the B series throttle body right? On my B series i just plugged the vacuum port for it inside the TB. Hope that made sense to u.</TD></TR></TABLE>

I was under the impression that pre-'92, Honda called it the EACV (electronic air control valve) and then '92-up they called it a IAC (idle air control). That's what my Chiltons manual says anyway. Aren't they the same basic thing?

In any case, my old '89 A6 IM has a FIV on the back of it (driver's side) but the '96 Y8 IM doesn't; just has the IAC/EACV on the pass. side back of it. It has a two wire connector, just like the A6 - I think I read somewhere the IM from a automatic Y8 engine has 3 wires.

How did you plug the port for it inside the TB? JB weld? I could test if this would fix it by waiting for the car to fully warm up, then remove the intake and cover the FIV port with my thumb right?

 

look at my post in this thread for pics and info...https://honda-tech.com/zerothread?id=573612

my guess to your idle problems is that your TPS is out of spec. should be 5.0V fully open and between .45-.50V closed. if your top end is correct you can adjust the idle voltage with the throttle stop screw and throttle cable tension. just probe 2 of the TPS wires(yellow & red if i remember right) with paperclips and turn ignition on and adjust till correct.

then set idle by using the helms...yes unplugging the iacv/eacv is included in that.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">Does the Y8 IM even have holes for the IACV ? I know u said IAC, but do u mean IACV? From what i remember, Y8 IM's have the IACV on the throttle body, and they have a 3 wire connection instead of a 2 wire. The FIV i believe is on the B series throttle body right? On my B series i just plugged the vacuum port for it inside the TB. Hope that made sense to u.
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auto Y8 IM/TB has a 3 wire iacv/eacv connected to the TB. the manual version has a regular 2 wire connected to the IM.

BTW...the iacv and eacv do/are the same thing just called different things. thats why i like to use iacv/eacv.

that fast idle thermo valve on the a6 manifold is not needed.


Modified by fastcrxsi90 at 8:46 PM 11/24/2003

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by fastcrxsi90 &raquo;</TD></TR><TR><TD CLASS="quote">
my guess to your idle problems is that your TPS is out of spec. should be 4.5V fully open and between .45-.50V closed. if your top end is correct you can adjust the idle voltage with the throttle stop screw and throttle cable tension. just probe 2 of the TPS wires(yellow & red if i remember right) with paperclips and turn ignition on and adjust till correct.</TD></TR></TABLE>

Thanks fastcrxsi90. I did check the TPS setting; it was at .51V closed. I reset it to show .45-47V closed, but the WOT still shows way over 4.5 V (its about 4.95, once it showed a hair over 5 V). It still hunts after setting the TPS lower.

I checked this by probing the center TPS wire (red/blue) and reading ground at the battery with the key on ignition position with the engine off.

I figure I don't want to change the stop screws to achieve 4.5 V on the TPS b/c this will restrict the airflow thru the TB right?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by CRXMR2SM2 &raquo;</TD></TR><TR><TD CLASS="quote">

Thanks fastcrxsi90. I did check the TPS setting; it was at .51V closed. I reset it to show .45-47V closed, but the WOT still shows way over 4.5 V (its about 4.95, once it showed a hair over 5 V). It still hunts after setting the TPS lower.

I checked this by probing the center TPS wire (red/blue) and reading ground at the battery with the key on ignition position with the engine off.

I figure I don't want to change the stop screws to achieve 4.5 V on the TPS b/c this will restrict the airflow thru the TB right?</TD></TR></TABLE>

i editted my post above...fully open the TPS should read 5.0V not 4.5V. that will teach me to go from memory instead of looking things up. the stop screw is only for the idle...it wont change anything for the fully open position.

i get the .45V from this - http://hondata.com/techidle.html
i actually set mine at about .47-.48 something in that range if i remember right...because above .5 and below .46 it would surge.

if you take off your intake and start the car put your finger over the hole for the iacv/eacv in the TB...you should feel it pulling air through it. i beileve it pulses open and closed and will stall if you completely close the hole off with your finger. if you dont feel it working the iacv/eacv might be bad. other than that reset the idle by:
warm engine then turn off
unplugging iacv
restart engine
adjust idle with set screw
turn engine off
reconnect iacv
reset ecu by pulling fuse
restart engine and idle in no load for 1 minute
recheck idle speed

 

If its the same valve im talking about (the one on the B series TB and it should have 2 coolant lines), then yes u can plug the port up with your thumb. If u look inside the TB, before the throttle plate, u will see two holes on the left side (closest to the firewall) and u will want to plug the bottom one. I did not use JB weld, instead i used a pretty good sized vacuum cap and i just shoved it in there. A lot of ppl tell me that it might come out but its a very very tight fit and it hasnt come out for about a year now. A friend of mine did the same thing and he has had no problems. However, the FIV valve gave me different symptoms. My idle would slowly climb and stay high if i let the car idle for a while, then i would stab the throttle and it would go down to about 750 rpm, then it would repeat. The "hunting" or surging is usually associated with the EACV, IACV, IAC or whatever its called on ur car.

Oh BTW, thanks for the info on that automatic Y8 IM, i will relay it to my friend who has the 3 wire one on the TB.

 

Might not be related but when my CRX had a problem with the idle going up and down, both at idle and under power. I would pull over and smack the distributor with a hammer. That worked great til I replaced the distributor and havnt had that problem since.

 

idle hunting is caused by a badly adjusted idle screw. youre getting too much air thru the TB and so the idle is too high so the ecu tries to compensate but just bogs, then goes back to high idle and continues the cycle. adjust your idle properly.

 

Thanks to everyone who took the time to help out. I'll get back in the garage and figure it out soon I hope.

Last question - can my static timing being way off cause/contribute to the problem? If so, is it possible to adjust the timing with the jumper in place, the engine fully warmed up, and the idle hunting up and down like crazy?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Tyson &raquo;</TD></TR><TR><TD CLASS="quote">idle hunting is caused by a badly adjusted idle screw. youre getting too much air thru the TB and so the idle is too high so the ecu tries to compensate but just bogs, then goes back to high idle and continues the cycle. adjust your idle properly.</TD></TR></TABLE>

That may be it, but 9 out 10 cars that come to me with that problem is associated with a bad IACV, but dont rule anything out.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by fastcrxsi90 &raquo;</TD></TR><TR><TD CLASS="quote">

if you take off your intake and start the car put your finger over the hole for the iacv/eacv in the TB...you should feel it pulling air through it. i beileve it pulses open and closed and will stall if you completely close the hole off with your finger. if you dont feel it working the iacv/eacv might be bad. other than that reset the idle by:
warm engine then turn off
unplugging iacv
restart engine
adjust idle with set screw
turn engine off
reconnect iacv
reset ecu by pulling fuse
restart engine and idle in no load for 1 minute
recheck idle speed
</TD></TR></TABLE>

OK, I've checked the FIV by checking for suction at the lower hose inside the T-body when cold (there is) and that it goes away when it's fully warm - in fact covering the hole with my thumb when it's warm does nothing to the surging idle. So this makes me think it's OK.

I tried adjusting the idle set screw with disconnecting the EACV but it's bottomed out all the way clockwise and the idle is still way too high (around 1200 rpm warmed up).

So what next? Test the EACV and see if it reads between 8-15 ohms at the terminals? Take it off the IM and clean it?

What about swapping the TPS sensor? I have another one I pulled from a Y8 throttle body . . .

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by CRXMR2SM2 &raquo;</TD></TR><TR><TD CLASS="quote">
OK, I've checked the FIV by checking for suction at the lower hose inside the T-body when cold (there is) and that it goes away when it's fully warm - in fact covering the hole with my thumb when it's warm does nothing to the surging idle. So this makes me think it's OK.</TD></TR></TABLE>

i dont understand what you mean by this...the y8 manifold/TB has one hole inside the TB going from the TB to the IM through the iacv/eacv. my b18a1 TB has an extra hole in the lower half of the TB that would go to the fast idle valve doohicky for the b18, but there is no corresponding hole in the manifold for it. if that makes any sence!

if your TPS readings are in check you shouldnt need to swap it.

when its idleing at 1200rpm...can you push back on the throttle disk or pull up on the gas pedal and drop the rpm a little? there is some adjustment in the throttle cable itself...just keep a meter on the TPS to make sure it stays in the correct range.

do you have the IAT hooked up? throwing any codes?

if you connect tap 12v/ground to the iacv terminals and it clicks then the iacv works. i dont think there is a 8-15 ohms reading for it.

do you have all of your vaccum lines run correctly? including the tiny one on the back drivers side that is for the origional cars AC? toward the bottom of this page - https://honda-tech.com/zerothread?id=573612 i included a vaccum diagram for the y8 manifold if you need it.

also what ecu are you using? obd0 w/ ghetto vtec, obd1?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by fastcrxsi90 &raquo;</TD></TR><TR><TD CLASS="quote">

i dont understand what you mean by this...the y8 manifold/TB has one hole inside the TB going from the TB to the IM through the iacv/eacv. my b18a1 TB has an extra hole in the lower half of the TB that would go to the fast idle valve doohicky for the b18, but there is no corresponding hole in the manifold for it. if that makes any sence!
</TD></TR></TABLE>

My throttle body is from a Integra; it looks just like this:



The EACV is supposed to read 8-15 ohms across the terminals according to page 6-47 here (http://tech.hybridgarage.com/tech/ma...supplement.pdf )

I do not have any gross vacuum leaks; I'm using that 1/8" nipple down on the bottom driver's side of the IM to feed the EVAP solenoid. Whether they're routed correctly or not, I have no idea. I just tried to run it as similar to what is was before as possible. The new TB has one less vacuum nipple so I couldn't do it exactly as it was before.

I'm using the original PM6 OBD0 computer; the VTEC solenoid wire is not hooked to anything yet but I was planning on using a V-AFC for that later. I may upgrade to a 2nd gen Integra computer and a B&M FPR as well.

Do I just pull back the carpet and look to see if there's a blinking LED on the ECU?

 

i am using a 90-91 B18A1 TB on my Y8 manifold. the TB has an upper and lower port. the upper port goes to the iacv/eacv and the lower port goes to nothing at all...it stops at the manifold.

i dont know what year/model integra your TB is off of...but...is the fast idle thermo valve actually on the bottom of the TB or is it origionally mounted on the bottom front lip of the corresponding integra manifold? because im guessing there is no "fitv" at all...there is no place to mount one on the Y8 manifold. can you possibly take a pic of your setup? does your TB have the MAP on the top of it or are you running the origional firewall mounted MAP?

as for codes pull the carpet back...and turn the ignition on and after the intial blink count the blinks for the corresponding code(s)...it will just keep repeating itself so keep counting until the same sequence of codes is repeated. if there are any at all.