Hey guys,

I know that this topic has been covered here and there, but i would like to start a bit of a discussion and get some help with my prob.

Problem - my idle surges from 1000 - 3000 rpm when cold, and 1000 - 1500 rpm when at normal operating temperature...

General Diagnosis - people seem to think that its the IACV.. i have taken this off and cleaned the meshy part, but did not make a difference.. i need to take it off completely but the two rubber hoses seem to be stuck on really bloody hard!.. I have looked for vacuum leaks also, but have had no luck.

I have realised that when turning on the air con, idle stabalizes at 1500rpm.. does this emphasis that the problem is the IACV? or is it something else?

also, the problem started to occur a few weeks after installing a big cheap aluminum intake.. which ive since returned back to stock!

 

i had this problem turned out it had to do with the map sensor wiring and iat sensor wiring.

 

Really? are you able to provide more detail please?

 

check your fast idle valve... sounds just like mine when i had that problem... take off your intake and youll see a hole on the throttle body, cover that with somethign and if your idle comes down to normal, then that is your problem... what happens is the valve itself unscrews itself and when it comes out like that, it causes your idle to be high like it is.... try that out and lemme know how it goes...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by xscape &raquo;</TD></TR><TR><TD CLASS="quote">Really? are you able to provide more detail please?</TD></TR></TABLE>

well it was actually the wiring with the safc, I was converting back to stock from turbo, and my idle was too high, like 1100rpms, so i reconnected the safc with the stock settings and my idle was back to normal, so I'm guessing it was just the wiring. I couldn't just disconnect the safc's pigtail, I would have to disconnect the whole wiring.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 94whtgsr &raquo;</TD></TR><TR><TD CLASS="quote">check your fast idle valve...</TD></TR></TABLE>The FITV is underneath the throttle body. Newer cars don't have a FITV, it's job is built into the IACV. What year?

When you installed your intake, could you have moved the base idle adjustment?

 

I hear ya, im having the same problem only mine goes from about 1100 to 1600 and drops... before i read that it had something to do with air bubbles or some such something and i took the cap off the rad. and let it sit for a second.... it stopped doing it for a while but now its freezing again and it will do it more often. I just had a new downpipe (if thats what its called) and O2 sensor put on (thanks to Mgags) so maybe they have something to do with it. hopefully this thread will help me solve my problem.

thanks all
-adam

 

My cousin has this problem in his DA. We tried cleaning the IACV and bleeding the coolant. We think its the FITV

 

Thanks guys!

Mine is a december '94 Vti-R (GSR)..

Ive always wondered about the FITV, which modles do/dont have them?

If i do have it, then im putting money on that!.. my IACV seems clean enough.. is it hard to take off the FITV, and can anybody post a pic of where it is?.. cheers

Also, it may be important to note that the problem started off being a 200 - 500 rpm surge, and gradually got worse and worse... would this be the FITV screw becoming more and more loose???..

cheers.

 

Ok heres a good idea just like someone said in here. i'll name them all. OK there is a screw on the throttle body that can cause this if it gets loose. BUT it cant get loose on its own unless its been manually loosened before because there is a gray putty in there that holds it still. That was my prob with my ls crx, it would loosen and my idle would go up and up then it would start to jump because ur getting too much air at idle so whats the ECU do? throws more gas in to make up for it then the ECU throws less in cause the idle goes down thats why it goes up and down.

Another is the air bubbles in radiator. 1 air bubble can turn into a huge problem especially with overheating why? water boils at what 220? and turns into steam. steam is hotter then water so makes more boil and soon enough ur car is red hot. Also cause problems with idle so take the cap of while its running and let it run for about 20 min. bring the rpms to 2000 let it sit for a few and keep doing that. Make sure u get the air bubbles all out and refil it all.

The iacv will usually throw a code 14 if its the problems, and im pretty damn sure the FITV would too but id check it anyway. so best bet, check the top 2 first, easy simple no parts to take off just time. those dont work then resort to fitv.

after that throw a huge wing on ur car the biggest loudest muffler u can find and make urself a type R

 

Thanks guys,

Well, did some more investigating last night and I believe its the FITV.

When the car is at normal operating temp, there is a great deal of suction out of the hole on the lower left side of the TB.. if i put my finger over it, the engine idles normally..

Now, just gotta find the time & energy (and my damn 10mm spanner) to fix it

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 94whtgsr &raquo;</TD></TR><TR><TD CLASS="quote">check your fast idle valve... sounds just like mine when i had that problem... take off your intake and youll see a hole on the throttle body, cover that with somethign and if your idle comes down to normal, then that is your problem... what happens is the valve itself unscrews itself and when it comes out like that, it causes your idle to be high like it is.... try that out and lemme know how it goes...</TD></TR></TABLE>
he is correct just make sure when you pull your throttlebody you have an extra gasket in case yours tears or rips. also dont overtighten your fast idle valve it will cause your rpms to be too low

 

What? so i need to take off the throttle body???.. damn!

i thought there were just three bolts on the FITV and two coolant lines?

please tell me im right!

 

im having the same problem with my 91 DA... this FITV where is it.. i have a sensor on my throttle body and if i unplug it and plug it back in it will stop surging but will idle at 2600 rpm at normal temp...

 

Had the same problem, my idle was caused by the FITV.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by xscape &raquo;</TD></TR><TR><TD CLASS="quote">What? so i need to take off the throttle body???.. damn!

i thought there were just three bolts on the FITV and two coolant lines?

please tell me im right!</TD></TR></TABLE>
dont worry it is easy all you have to do is disconnect a couple hoses and your throttle cable it is like a 15-30min job form start to finish

 

Someone posted about how the guts of their FITV came loose. So he tightened it back up & put it back together. Search in archived threads... When it's all warmed up, the FITV should be closed so covering up it's port should make no change. Make sure you're not covering up the port for the IACV.

I think maybe '95(?) was the last year for the FITV. It's function was built into the IACV.

Setting base idle on my '95 GSR is probably about the same for yours. December '94 would be a '95 model-year, right??
1 - Engine completely warmed up, spark timing set correctly.
2 - Unplug the IACV elecctrical connector. It'll want to stall, so hold the idle up manually, gently let it down.
3 - Adjust idle screw so it idles at 500.
4 - Plug IACV back in, it'll bring idle back up to 800 where it's supposed to be.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 91_teggy &raquo;</TD></TR><TR><TD CLASS="quote">im having the same problem with my 91 DA... this FITV where is it.. i have a sensor on my throttle body and if i unplug it and plug it back in it will stop surging but will idle at 2600 rpm at normal temp... </TD></TR></TABLE>I think for you the FITV is #9.

 

see number 22? its pointing to an O-rin but that whole assembly i believe is th FITV and the other ones that looks like it thats behind the IM, thats the IACV.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by tRex99 &raquo;</TD></TR><TR><TD CLASS="quote">see number 22? its pointing to an O-rin but that whole assembly i believe is th FITV and the other ones that looks like it thats behind the IM, thats the IACV.</TD></TR></TABLE>
this man is correct.

 

Is there any problem with unhooking the FITV and the IACV like hondata says to do on there website. I have the unit under the throtle body unhooked and a plate has been put in its place. The unit on the back of the intake manifold is still in place. I'm not sure at this point what is causeing the surging problem but it may be that my 3bar map is to far from the original location and that it is teed to all hell with boost controlers and guages.

Let me know if you have any insite.

Matt

 

Well, to make it easier for you guys in the future, you do not need to take off the throttle body, heck, i didnt even take off the FITV.

on the back (towards the firewall) there is a gold plate, held on with two 8mm bolts. basically reach behind and take these off. then use your hands, or a small flathead screwdriver, and twist the outer part back in as far as possible.

not recomended for people with big hands though!

 

my rex had the same problem and it was a brass screw on my throttle body. i just turned it all the way in and that fixed it. i hope this helps. i had about 50 hours in chasing down this problem on my little rex. i have not had a problem since. let me know if it helps

 

this is easy 2 fix. take your intake hose off and look under the throttle body. U will see three 10 mm screws, take um loose. there will be a cover plate over that valve with 2 8 mm screws, take 1 out and loosen the other 1. get a big chizzle and press the brass buttom in and rotate the outer plate clockwise untill it stops. bolt it back up problem sloved.

 

where do the two hoses go that come off of the FITV (h22a_obd1)??? I went to take mine off today so i could tighten up that screw and these hoses are capped off! I need to know where they go so i can hook everything up the way it's supposed to be........i'm not trying to bypass the FITV

I can't seem to find a diagram anywhere.........