wierd idle on d16y4

[[ricer]]

recently after getting a new exhaust and intake on my car the car has been idling quiet funny.

first it started normal (cold start) then once the car got warmed it dropped to 900-1000 then after a few seconds it would start bouncing like 1000-1500-1000-1500-1000-1500-1000-1500 rpm

then a few mornings ago i've started it up again, cold start again. now it starts and revs at 900, then as the car warms up, the idle goes up too! so on normal operating temperatures the car idles at 1500rpm :eek:

it seems as like some of my sensors have been cut and moved. but i dont think and that would effect idle? one is the intake temp sensor i think and the other is the one that sits at the headers..

any help would be much appreciated :thumbsup:

[EuroDude]

When you change the intake and/or exhaust, you should reset the ECU so the it can learn how to idle properly again. Remove the BACKUP fuse for a minute to reset it.

If its still bouncing, then you need to clean the IACV filter and screw in the FITV Valve http://www.emotors.ca/Articles/97.aspx
Also clean the Throttle Body of Carbon deposits.

[[ricer]]

cool i'll try that out
i think it must be something to do with the coolant side of things beause of the way oh how when the car warms up, the revs higher but when the cars cold the revs lower..
its like its working back to front....

[EuroDude]

Yep the exact same thing happened to my Civic. I think the Throttle Body clean corrected the problem if I recall correctly (cleaning the IACV filter didnt do much), but you should also clean the FITV and IACV to get the car idling properly in general. Do an ECU reset after cleaning ftw

When you clean the Throttle body, make sure you also clean in the Idle Bypass Hole so the engine can breath properly during idle. (Spray some carby cleaner in the hole/pipe in front of the Butterfly Valve).

Here are some DIY's
http://www.ozhonda.com/forum/showthread.php?t=35488
http://www.ozhonda.com/forum/showthread.php?t=4693

[[ricer]]

cool thanks for your help
so ur one was also idling low when cold but high when car was warmed up right?

[m3ntAL_l2]

;1111698']so ur one was also idling low when cold but high when car was warmed up right?

shouldent it b other way around??

[[ricer]]

it should
but thats how mine is atm haha

oh and when u rev the car... the revs drop dramatically and then build up again
i had a look at the fitv and it looks hard to take out :(

[EuroDude]

;1111698']cool thanks for your help
so ur one was also idling low when cold but high when car was warmed up right?

Yep it was idling normally at 1500rpm when cold, but when it was warm it was jumping from 1000rpm to 1500rpm.

You dont have to adjust the FITV valve since your cold idle seems ok, but it wont hurt to check it anyway. Its not hard at all, all you need to do is release two 12mm bolts to drop the FITV module.


If the Cold Idle is idling above 1500rpm, adjust the FITV
If the warm idle is idling above 800rpm or jumping up and down, clean the IACV and Throttle Body.

[SLPJCooL]

I don't think EK1's have a FITV valve....not that I can find it in my EK1 anywayz

[hayashi_1986]

There's one other thing you may want to check. If the throttle body gasket is leaking or old and worn, it could cause incorrect pressure readings from the MAP sensor, causing the engine to idle erratically.

Check that the gasket is ok and intact, then give the manifold a good clean with a snake brush and some carby cleaner. Make sure the cleaner is sensor safe, otherwise you could be looking at a new MAP sensor (40 bux).

If you really want to make sure it's not the TB or gasket, give the whole thing a decent clean with the TB OFF. Just remove it with a 12mm socket, ratchet and ratchet extension. Don't slack off on the cleaner, use liberally (if your going to do this, better take the MAP sensor off). When your done slap on a new TB gasket (18 bux from Honda, and prime it with some WD40 for better adhesion), but before that clean the old gasket compound off of the TB and manfold, and give it a whirl without the intake on. You'll see a massive plume of smoke come out of the exhaust...it's ok lol, it's just the carby cleaner burning off. Once you crank the engine, rev it a bit so it doesn't bog out.

To finish things off, reset ecu, leave it to idle till the heater fans come on, and vualah~! Idle problem SHOULD be gone, and you'll have better, smoother response. Take it for a spin (don't rev it hard, otherwise it could cause the idle to be too low or high).

This fixed my idle problems easily.

Anyone needs to add anything, that'll be good.

Cheerz!

[[ricer]]

wow that sounds hectic but do-able i guess
i guess if i had bought a skunk 2 intake manifold or something i'd have more reason to pull mine off haha

[hayashi_1986]

Haha, don't take the whole mainfold off (if that's what you mean), just the throttle body. The snake brush is for the manifold so you won't have to remove the whole manifold.

[EuroDude]

Yep it could be a more complicated idle problem, but most of the time the engine simply needs a good clean. Try the easy stuff first then move on to the hard stuff if all else fails.

I am 75% certain a throttle body clean will solve this particular problem since my Civic had the exact same symptoms :thumbsup:

[[ricer]]

i just sprayed throttle body cleaner into the throttle body today...
spray abt 1/4 can... no improvement... going to move onto more harder ways tomorrow...

[hayashi_1986]

Once you start getting into it, it'll become quite clear and easy actually :) DIY's make you feel good lol especially when they're done right. :)

[destrukshn]

Once you start getting into it, it'll become quite clear and easy actually :) DIY's make you feel good lol especially when they're done right. :)
and work.
lol.

[kyle]

but you should also clean the FITV

D16y4 doesn't have a FITV, no OBDII Cars do.

[kyle]

;1111022']
it seems as like some of my sensors have been cut and moved. but i dont think and that would effect idle? one is the intake temp sensor i think and the other is the one that sits at the headers..any help would be much appreciated :thumbsup:

You didn't take out your O2 sensor did you? Hahahahah Thats like the most important sensor of all.

[EuroDude]

;1111860']i just sprayed throttle body cleaner into the throttle body today...
spray abt 1/4 can... no improvement... going to move onto more harder ways tomorrow...

Did you also spray into the Idle Bypass hole in the Throttle Body (its near the opening of the TB before the Butterfly)? If thats clogged up, the engine will idle badly.

If that doesnt help, clean the IACV filter :thumbsup:

[EuroDude]

D16y4 doesn't have a FITV, no OBDII Cars do.

True dat. was thinking of the EG D16's :p

[hayashi_1986]

and work.
lol.

Totally true that one lol Feel real bummed out when it doesn't work!

[[ricer]]

You didn't take out your O2 sensor did you? Hahahahah Thats like the most important sensor of all.

narh cause when i unpluged it the engine light came on straight away lol

just woke up now... going to try again...
and yep i did spray into the little hole before the butterfly.. had to keep revving the motor cause it sounded like it wanted to die so much

[[ricer]]

guys i've spent the weekend pulling off the throttle body and cleaning it
even cleaned the iac valve and the car still idles higher then normal once its warmed up
no adjustment has been made to the idle screws as the paint is still on it.
tried running the car last night with no radiator cap to see if any air bubbles in the coolant but nothing...
only other thing i can think of is a vacuum leak.

any other things i can look out for?

[EuroDude]

Tried resetting the ECU?

Perhaps it's the throttle body gasket after all.

[[ricer]]

yup reset done a few times since i disconnected the battery when ever i pulled out all the harrnesses.
im going to spray carby cleaner around where the gaskets are. i've read that if the revs change then thats where the leak is...

[[ricer]]

update
been reading up alot on the problem. i found this


Make sure your car is completely warmed up. With it running, take the intake off the TB. There are 2 holes right in front of the throttle plate, these are the holes that feed the IACV (top hole) and the FITV (bottom hole). With your finger, cover up the bottom hole (it should NOT be sucking if your car is warmed up). If the idle goes down the FITV is to blame, either get a new one or take it apart and screw the valve completely closed

well when i block the bottle hole my car wants to stall....
it was said my car didnt have a FITV. does anyone with a d16y4 know if does or not? i cant find it on mine...

[muhhan]

I could not find the FITV either and doubt it exists on these engines. The IACV is also of a different design to the one that is illustrated on the IACV clean out DIY on this forum. The one on the D16Y4 is mounted on the underside of the throttle body. The hoses that connect onto it are very difficult to get off, I will most likely have to cut mine off and replace with new ones.

I took the IACV off in my car (with D16Y4 engine) and couldn't figure out how it should be cleaned. It appeared greasy inside. I'm not sure if it is supposed to be this way for lubrication?!? There is also coolant in the IACV so place towels underneath when you take it off.

In the future I will likely remove the entire throttle body assembly to give the whole thing a thorough clean up and replace the seals/rubber rings as well.

[EuroDude]

When you remove the IACV you should see a small filter with black gunk in it. Grab some Carby cleaner and spray the filter clean, and also spray into the various IACV cavities

[[ricer]]

my problem is my idle motor
getting it changed soon to a Y8 one

[muhhan]

Idle motor?!? What's that? I don't think idle is controlled by a separate motor.

[[ricer]]

i think i may have heard wrong
but once its fixed i'll post it all back up
for now my idle has been lowered with the ECU i think
will get back to this thread when its all fixed up

[SLPJCooL]

Have you though about changing/cleaning your PCV Valve? Did the trick on my weird idle problem. And I have the same engine (d16y4)

[hayashi_1986]

Like I said much earlier in my other post, if all else fails, change the TB gasket. Last resort if nothing else works.

[Fo55il]

reincarnate

[[ricer]]

it was my throttle body
it was stuffed

changed to another one and fixed the problems... all good

[Fo55il]

yeha my throttle body was dirty too