wondersparrow

[QUOTE=OP](for B16A2, d16y5,y8)if the engine speed drops or stalls, adjust the (base) idle speed, clean the ports in the throttle body as necessary. if the engine speed doesnt drop, or doesnt stall, replace IACv.[QUOTE]

What is meant by "drop"? when I unplug my IACV, my idle goes from ~1000 (it bounces between 1100 and 1600 which is one of my symptoms) and drops to a steady 600 or so. Should it drop right to the point of stalling? Is this maybe/likely a manifold gasket leak?

Sparky

RaWrZie

I covered the bottom hole and my car stalled.
What's that mean?
Whats the next step?

wondersparrow

Was it warm at the time? I seem to be confused about which port goes where. I'll look a little more closely after work when I take it apart again.

RaWrZie

Nah it wasn't warm.
Just tested to see if the idle when down if I covered the bottom hole of the tb.
It went down and I guess because I had it there for too long it shut off due to not getting any air.

Still need to know what to do next.

wondersparrow

Well if what I think is right. The bottom one goes to the FITV which should be closed when the car is warm If it is cold, the FITV give is extra air so it can idle high.

RaWrZie

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by wondersparrow &raquo;</TD></TR><TR><TD CLASS="quote">Well if what I think is right. The bottom one goes to the FITV which should be closed when the car is warm If it is cold, the FITV give is extra air so it can idle high. </TD></TR></TABLE>

Ummm yeah you are right. Just saw another thread.

Top = IACV.
Bottom = FITV.

So what does it mean?

How can I check if the IACV is working? Same test through the top hole of the throttle body?

wondersparrow

is there a vacuum on the top hole at all? if not your IACV may be stuck closed. if you unplug the IACV, does the idle change?

RaWrZie

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by wondersparrow &raquo;</TD></TR><TR><TD CLASS="quote">is there a vacuum on the top hole at all? if not your IACV may be stuck closed. if you unplug the IACV, does the idle change?</TD></TR></TABLE>

No vacuum at the top hole(IACV?) but vacuum at bottom hole(FITV?).

I'm guessing the IACV is stuck close because after I took it off to see if the idle changed like you said...it sounded like complete ****.
Bouncing from 1k-2.5k.
Which is a damn lot. Lol.

Right now its steady with it on but around 1k+ rpm.

What do I do if the IACV if it is stuck close?

And is the FITV fine if it's vacuuming really strong through the tb hole?

RaWrZie

The clip with the 2 wires on my IAT were cut off before I bought it...

Would that play into getting a CEL 14?

Aside from the fact that I need to do something about my IACV since it seems to be stuck closed.

Any input will help.

wondersparrow

both the fitv and iacv are really easy to take off and clean. I used https://honda-tech.com/zerothread?id=1564019 and https://honda-tech.com/zerothread?id=1575913 . only issue I had is the gaskets/o-rings were all dried and needed to be replaced. that seafoam spray stuff is amazing. it will clean the black right off carbon.

RaWrZie

Well I've cleaned my IACV. So I know it isn't that.
But it could be because it is stuck closed. And I have no idea how to fix it.

My FITV is a bitch to get out. But I am getting a strong vacuum from inside the FITV hole in the throttle so I am kind of ruling that out.

So I am thinking it is my IACV being stuck closed.
And/or my IAT wires(2) had been cut.

portaman03

Jonathan_ED3

Sorry to bump this old thread, but I need to ask!

What the heck does "should be around 10%" mean?

In what unit of measurement? 10% of what? How do you measure "10%"?

Curious about this as I have a very stubborn code 14 that I cannot get rid of.

It's OBDI d16z6 if it matters.

tysonboy

my car does the same thing idles at 1500/jerk ect.......... i will try to do this, and my car is a 1999 ek with a b16a2......

ddessens

recently replaced my 94 civic d15 engine, old was worn out 275k no oil pressure. new (used one) has about 130k. getting code 14 iacv. replaced iacv with original one, which had no codes when running. still have code 14. no idle problems, just jerking when on trailing or light throttle,ok on acceleration or steady throttle. any help would be appreciated

ddessens

thanks for the heads up, been working all week will try out a few things this weekend and pass along any info--thanks

zenjah

just to let everyone know, i was having slightly rough idle and when driving, accelerating, cruising etc. engine would repeatedly and unevenly, rhythm-wise, cut out and then go back to regular rpms, so like a bunch of kind of cut out and then resurge back to normal rpms, more so in higher rpms and less near idle, but still during idle and slow acceleration it would do the same thing.
when i revved the engine in neutral, it didn't have any noticeable surging and seemed fairly normal.

so i change the spark plugs and no difference,
recently installed new distributor so
next, changed the spark plug wires since the car's old and i haven't done that before, and $40 for a new spark plug wire set, completely solved the problem of cutting out, surging engine.

so the rough idle and surging seems a result of cutting out, i assume due to lack of electricity through what must have been shorting out through spark plug wires.

i thought i was going to have to go through the fuel filter, fuel pump, among other things mentioned here, but this worked and might save you some money.

OneBadEM1

So I been having this P0505 Idle System Malfunction code popping up on my 2000 Civic Si, I've had the IAC replaced wasn't the issue, i replaced the TPS and set to correct voltage which fixed the stalling part of it, made sure my timing was right and it still cuts out when the CEL light comes on. The ECM is chipped i dont know if that causes a difference in idle speed though. Any ideas??

Rudy N Alvarez

I have a 2000 honda civic ex d16y8 with idle problems i can't adjust the idle on it i get the p0505 code on it i changed the IACV because the other one was bad and gummed up bad i broke the ECT and go a new one put in can someone please help me out on this damn thing
Map sensor works tps works i stilll get the codes i am pretty sure i don't have any leaks

Dave2000si

i have a 2000 civic si and im having problem with the p0505 code i tried to clean iacv and that didn't help so i bought a new one and i put it on and it runs better but still idles to high and when i went to get the code wiped they told me i have to drive it for arounf 80 miles so the ca will get use to the new part is that true...but when i was driving the car i came to a light and it started to idle up and down between 1200 and 1700 rpms and the check engine light came on again and it started to run bad again could i have gotten a bad iacv from napa or is there somthing else...all hoses are good

Former User

You can clear codes yourself. See codes sticky.

Did you read the first post in this thread? A bad IACV is only one possible cause for P0505. In fact, a bad IACV is probably an uncommon cause.

Dave2000si

yeah i read it.. so i douldve gotten a bad valve then?...should i spray some kid of throttle body cleaner in there incase it clogged up?...ect could realy cause this problem?

omerfar23

i am having idle issue, major bucking under throttle from rest, I recently had a my brake line changed. please help? the car idles at 1500

SiCivicHB1993

I also have the revving issue - I bought a brand new IACV and IT STILL DOES IT! Going to try to clean up the FITV and see if that does anything. This is really starting to bug the crap out of me. I cant believe it wasnt the IACV!

Any Thoughts?
Thanks,
Rob

Former User

Old thread closed.