HaTcH_BmX

help please... it's really annoying... it jumps from 2200 or so to 1000... up and down ....ALWAYS... but when it's cold it idles really high... at like 2700 for 40 seconds... and then the up and downs... i checked the iacv it's fine.. changed the fuel filter...checked for vaccum leaks...nothing. the only i havent checked are the injectors... how do i know which on is bad if any??
any more options i should look for..
thanks

ps: i searched... bumped all the threads with the same problem... but none helped ...

edit: it's a d16z6

si0385.

check ur FITV

96 EX

sounds like a vaccum line or something to me

AutoXer

Test for a vac leak by spraying carb cleaner all around where the lines are. If it surges, that's where your leak is. A simple test that may save some aggrivation. If it's not that, I'd check the FITV.

tpr

Set your Base Idle

1. Warm the car completely up.
2. Disconnect the IACV.
3. Set base idle to 500-550 RPM using the idle speed control screw (above and to the rear of the throttle body opening as viewed from the passenger side. Turn it clockwise to slow the idle, counterclockwise to speed it up).
4. Reconnect the IACV.
5. Shut car off to clear the IACV code (check engine light).
6. Start it up and if it was the base idle setting it should idle fine.

AutoXer

But you should only mess with the idle if you know that absolutely everything else is working okay. If there's a problem, messing with the idle is just a band-aid and not a very good idea. You really shouldn't have to ever touch that screw.

RTI

do you have a fast idle thermo valve (FITV)? If you do, I would bet this is the problem. The piston that blocks airflow when warm is not positioned properly, so it is allowing too much airflow when cold, causing the high idle. I think the IACV is then correcting, which is causing the oscillation. I know the FITV on a OBD1 B18 can be adjusted by turning the white plastic piston. I had a similar problem and this fixed the problem.

HaTcH_BmX

thanks for the replys guys... i just got up from a night work shift... i'll try all those out and see what happens..
thanks again

vtakvtrak

I have teh same issue also, 98 gsr motor in a 93 eg..... mine goes from 1500 rpm to 1000 rpm then back up and back down, it does this when im at a stop light after the car is already warm....... not sure what the problem is either, some say its the p28 chipped, which is notorious for this... any thoughts?

JDMlyfestyle

IACV and FITV... mine are deleted off the motor. there is a thread. by Honda-driver search for it

HaTcH_BmX

im trying to find that thread but can't find it...i took the valve out and it seemed fine.. i blew through the holes and it was not clogged or anything(coolant tastes really good btw..lol)... but im not sure if im checking it the way it should be checked...how do you inspect it for being good or bad??...also the FITV is located under the TB, or behind?? i dont think my car has a FITV lol...there is a hose that goes from the motor to the IACV... and one from the IACV to the throttle body.. but i thought there was a hose going from the IACV to the FITV... but there are only two... and one that goes to the motor and the other to the TB... im lost here..
help

HaTcH_BmX

ohh one more... where does the vaccum hose that is next to the map sensor go to??
thanks

Slamaccord

iTrader: (1)

You could have air bubbles in your coolant system. Did you try bleeding your coolant system?

johnecon2001

Try checking the ohm reading on the TPS sensor as well. If it's off by just a little it can have the same effect.

HaTcH_BmX

.. everyone thinks im a ricer that likes to rev the car a lot...lol..
anyways.. this is so stressful man... i took the FITV out... took it apart to see that the white plastic thing that holds the valve back was loose... so i tighted it up... GREAT...i was so happy... it idled normal for like 5 mins and then it started doing the up and downs... the thing is that it doesnt idle as high anymore... but the up and downs are still there but not as high as before.... does the IACV come apart like the FITV... is there a chance that it's clogged, freezed??? how do you check if it's bad or good??
there is a nipple on top of the TB... is there supposed to be a hose in there... cause there isn't one... and where would it go to??
thanks...

HCivExoo

You can check to see if a IACV is working if you put two wires on the plug and connect the two wires to the battery pos and neg doesn't matter which one goes where. If you hear the vlave click its good.

you can also just unplug it with the car idling, if everything is correct the car jsut just about stall out or cut off when you unplug it. If it doersn't you ahve a vacume leak.

The reason the idle jumps up and down when you have a bad vacume leak is the ECU is just the IACV all the way to get it to idle down and it basically knows it shouldn't have to it opens it back up and up and down idle is what you get.

you can check IM gasket, TB gasket all of the vacume line from the IM to the evap canister

hogsnot

Had the same problem with a 1994 civic dx. I shotgunned the problem and got it fixed, I not sure which procedure actally fix it. The things I did

1. removed and cleaned the iacv
2. " " fitv
3. checked for vacuum leaks...found none
4. cleaned the throttle body where the butterfly makes contact
5. oiled the throttle cable
6. when cleaning the iacv and fitv take them apart as much as possible and clean throughly

HaTcH_BmX

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by hogsnot &raquo;</TD></TR><TR><TD CLASS="quote">Had the same problem with a 1994 civic dx. I shotgunned the problem and got it fixed, I not sure which procedure actally fix it. The things I did

1. removed and cleaned the iacv
2. " " fitv
3. checked for vacuum leaks...found none
4. cleaned the throttle body where the butterfly makes contact
5. oiled the throttle cable
6. when cleaning the iacv and fitv take them apart as much as possible and clean throughly</TD></TR></TABLE>

done all of them already... nothing...can someone tell me if the nipple on top of the throttle body next to the map sensor has a hose going to it??? where does that hose come from??
thanks

HaTcH_BmX

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by HCivExoo &raquo;</TD></TR><TR><TD CLASS="quote">You can check to see if a IACV is working if you put two wires on the plug and connect the two wires to the battery pos and neg doesn't matter which one goes where. If you hear the vlave click its good.

you can also just unplug it with the car idling, if everything is correct the car jsut just about stall out or cut off when you unplug it. If it doersn't you ahve a vacume leak.

The reason the idle jumps up and down when you have a bad vacume leak is the ECU is just the IACV all the way to get it to idle down and it basically knows it shouldn't have to it opens it back up and up and down idle is what you get.

you can check IM gasket, TB gasket all of the vacume line from the IM to the evap canister</TD></TR></TABLE>
i'll try that in a min

HaTcH_BmX

I FOUND THE PROBLEM... it's the IACV... i put electrical tape on the two holes like harv (1700anddroping) told me and it idles super normal now... quick question though.. what will happen if i drive the car like this for a few days until i get a new valve?? coolant still pass through it... but the holes are bloqued now...
thanks

tpr

I am almost positive that by setting the base idle to the correct RPM the problem will be solved. Have you tried that yet?

1. Warm the car completely up.
2. Disconnect the IACV electrical connection.
3. Set base idle to 500-550 RPM using the idle speed control screw (above and to the rear of the throttle body opening as viewed from the passenger side. Turn it clockwise to slow the idle, counterclockwise to speed it up).
4. Reconnect the IACV.
5. Shut car off to clear the IACV code (check engine light).
6. Start it up and if it was the base idle setting it should idle fine.

HaTcH_BmX

yes... i did that the first time you told me but didnt fix my problem.. i found a quick solution but im not sure if it will break something up if i drive it like this...
will the electrical tape solution affect anything if i drive the car like this for a couple of days???

HaTcH_BmX

help

1700anddroping

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


no it will not hurt any thing....but i also told you to attach the iac back
to the manifold.it will idle normal untill there is a hole burn in the tape from the heat of the motor.but i have driven them like this for 2 weeks.


this is just a quick fix...whether or not you fix it is up to you.but like i said
you need to check for a vacum hose being off to.do this by putting your
hand over the throttle body.if the car dies.you do not have a leak.if the car does
not die you do not have a leak.


harv

HaTcH_BmX

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 1700anddroping &raquo;</TD></TR><TR><TD CLASS="quote">


no it will not hurt any thing....but i also told you to attach the iac back
to the manifold.it will idle normal untill there is a hole burn in the tape from the heat of the motor.but i have driven them like this for 2 weeks.


this is just a quick fix...whether or not you fix it is up to you.but like i said
you need to check for a vacum hose being off to.do this by putting your
hand over the throttle body.if the car dies.you do not have a leak.if the car does
not die you do not have a leak.


harv</TD></TR></TABLE> ... this guy knows his **** !!!! harv you are the man..
so if i put my hand on the throttle body while running and the car dies i have a vaccum leak?? you said not on both.. so im confused there... lol