gstrudler

Update: loosened throttle cable and adjusted throttle plate both ways with no change. Going to try a drain and fill tonight and hopefully be done with this.

xxervio

So i have 2 types of idle bounce. one is the normal bounce from 1k to 1500, i took the IACV off and tried to clean it out good but it didn't help. my coolant is good. I think maybe my IACV is just bad. The other bounce happens only when i first start to drive. i usually have to turn the car off and restart it and it goes away for a little then comes back. i have to do that about 3-4 times and then it's finally gone. this bounce usually bounces between 1100 to 1400 and it bounces really fast. when this bounce happens the car jerks around when i accelerate and deccelerate thats why i have to restart it.

I am thinking it's the FITV? please correct me if i am wrong or might know it's something else.

gstrudler

Let me know what you find out; I too am beginning to think my IACV might be bad. Randomly tonight the bounce stopped though. At the same time, however, I picked up a whining noise that sounds like it might be coming from the IACV, so I don't know if it broke or what, but the car seems to be running fine right now (although I haven't started it cold yet).

xxervio, I have my doubts as to the FITV. The FITV is simply "a thermowax plunger" (according to Helm's) that allows extra air into the IM based only on the engine coolant temp. It's a very basic mechanical system. To test it, pull your intake, let the car warm up to operating temp and then cover the lower hole in the TB. If the idle drops, you have a bad FITV (this too, is according to the Helm's manual).

Toanz

well my idle doesnt bounce, but i am having problems. When i rev the engine up
and let it drop back down, it almost wants to stall on me. THe idle will then go back up to around 600 rpm. I blocked off that lower port in the TB with my finger and the engine stalls right away.

Help please

Toanz

anyone?

Jos3ph

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Toanz &raquo;</TD></TR><TR><TD CLASS="quote">well my idle doesnt bounce, but i am having problems. When i rev the engine up
and let it drop back down, it almost wants to stall on me. THe idle will then go back up to around 600 rpm. I blocked off that lower port in the TB with my finger and the engine stalls right away.

Help please</TD></TR></TABLE>

I'm bringing this back from the grave. So i'm currently having the same problems as Toanz, but instead, for my car the engine stalls out unless i put some gas. Anyone know what can be causing this problem?

bb6_00

My FITV has been eliminated, I clean out the IACV and get the 1k to 1.5k bounce all the time. If i put a light a pressure on the gas pedal for a couple seconds it stops. Kinda fustrating especially with all the lights I have to stop at.

any suggestion, just replace the iacv? or what?

btw: it has a 68mm type r throttle body

samurhai

ever find the solution gstrudler?

danewickenhauser

aweseome post, fixed all my surge problems

ParkerSi4ws

thanx for all the info. fitv ended up being my prob. now im not embarassed at red lights anymore....lol

oneslowxa

Just bought a 97 lude with the same problem. I already cleaned out my tb and adjusted the idle screw. It just recently started to bounce, I'll check the have FITV tomorrow.

First post!

b18cDelSlo

I fixed my idle surge this weekend! Thanks to this thread.

Cleaned the IACV, nothing changed. Unplugged it and no change to the idle.

I then took the CAI off and plugged my finger over the bottom hole. THE SURGE WENT AWAY!

I was so happy haha. I took the FITV off and the little white plastic piece that unscrews was all the way off. But I didn't want to take any chances so I just made a block off plate out of a distributor cover from an old 13b rotory engine that was sitting in my garage. problem solved for free!

I've had this idle surge for over a year and got to where I refused to drive it just because the surge was so bad. I wish I would have found this thread a long time ago.

thanks for the info!

StangBanger

Sweet.. thanks to this write-up i managed to fix my jumpy idle myself. Thank god for that because money is tight but that damn jumpy idle was a pain in my a$$.

gstrudler

hey samurhai, sorry just saw your post. it was my FITV after all that plus some air in the system. this electric water pump has been the bane of my existence. the first time i tightened down my FITV and it went away for quite awhile. however, my idle bounce came back about a month ago when i did some working on my cooling system, and i'm almost positive i've still got air in there somewhere; i think the ewp is messing me up when i'm trying to bleed the system b/c the install location in the directions is retarded. i've got to replace my headgasket soon and am going to be changing the location of my ewp when i do, which will hopefully help things out.

JimmH22

Hi guys. It's my first post here. I find a lot of info here and I finally register.

I have the same problem, It bounce from 1k-1,5k cold and hot now. But when the problem begin, it was just when it cold.

I put my finger in the upper port and it stop bouncing. I clean the IACV, no change. I put 12V on the selenoid and it open about 1mm (less 1/16 inch). Is it normal? Should I replace the IACV? The IACV is about 330$ at the dealer, I just want to be sure.

nemesiskrp

bump to this, I have the same prob... when you let off the gas from a rev, the idle drops below the target idle, than goes back up to normal... just does not feel or sound right lol anyone have a tip?

gstrudler

check your base idle; unplug the iacv and see what happens.

el_espiritu

Hey guys, I've got an 87 CRX with ZC1 engine (DOHC, non-VTEC) and my idle bounces when engine is warm. I read the thread carefully, but I'm not sure if we talking about the same parts. My PGM-FI system works with a lot of mechanic, non-electric. My EACV valve has no electric plug, just 2 coolant hoses which lead into a thermo-valve. And this one works, I checked today.

I also cleaned my throttle body completely, and I tried to close the second hole like thread stated, but I have only 1 hole and if I close this one the whole engine stops.

I also bleeded the cooland system, there is no air in it.
What can be the problem here?

danewickenhauser

I am getting a bounce between 1k and 1.5k. The problem goes away when i plug the top hole. I read all these posts but i still can't figure out what that means haha. Also, plugging the bottom hole doesnt do anything for me, there is no suction on that hole, is that normal? I am getting a CEL for knock sensor (just replaced KS since i broke the old one taking intake manifold off when i did my head gasket). Could KS cause a bounce? Throttle body is clean (plate closes completely) and i bled the coolant. I am very frustrated, any help would be awesome thanks!

aleks77

I had a bounce problem, and here is what it was, please note on ACCORDS (F22) it seems that the holes inside the throttle body are: bottom hole = IACV and top hole = FITV

alright guys, figured it out, i had a spare intake manifold laying around, so i took it apart, and blew compressed air into the top hole inside the throttle body, the air came out of the FITV so i blocked that hole, and the air came out of the #9 in the pic below, VALVE ASSY., AIR BOOST. So i blocked it off on my car, and voila, car runs perfect I think i must have busted the valve inside this valve when i blew it out with compressed air (because it had some metal shavings in it). So for future reference:

Top Hole = FITV + Air boost
Bottom hole = IACV

danewickenhauser

When i plug the top hole, the surge goes away. Bottom hole does nothing. Unplugging IACV makes it bounce but really fast/tight between 1000-1200. Bad IACV?

taimysho0

helo my problem is same, idle fluctuates although not quite as much anymore since i cleaned the th and iacv. however, the rpms idles at about 1.5k and the engine sounds like its idle is fluctuating. i cleaned:

throttle body with cleaner
iacv with cleaner
replaced brake booster vacuum hose

and STILL same problem, any suggestions? i have a 00 civic Si so it does NOT come with a FITV

4G92

iTrader: (1)

so the holes inside on the left of the throttle body change up between the h23/22 to f22a?

Wicked13

And print! Hopefully this will help me with my friends Prelude.

sispeeddemon

Ok, i Have read this post and the ones on PP.com. But my bounce is kinda different. It is fine all summer long, no bouncing/surging at all ever. But once it gets late fall/early winter, about 45-50degrees (F) or less outside it starts. But it doenst do it all the time. Only when the car is fully warmed up and driven for a mile or so. When I unplug the IACV it stops. So from what Im getting from this post is that I have a bad IACV? But then why doesnt it do it in the summer too? Please help me. I dont wanna buy a new IACV if thats not the problem. What would make it only do it when its cold outside???