Troubleshooting Idle Problems - Honda Forum : Honda and Acura Car Forums
 
 

» Auto Insurance
» Featured Product
Wheel & Tire Center

Go Back   Honda Forum : Honda and Acura Car Forums > Performance - Tech > Performance Tech > Engine Tech

SuperHonda.com is the premier Honda Forum on the internet. Registered Users do not see the above ads.
Reply
 
LinkBack Thread Tools Display Modes
Old 12-11-2005, 11:40 PM   #1 (permalink)
Type-S Member
 
Cautela's Avatar
 
Join Date: Oct 2002
Location: California Dreaming
Posts: 2,159
Car: '94 Integra Ls/vtec-Turbo (now GSR proj), '93 R33 Skyline GTS-25t (Sold), '04 RSX Type-S (new whip)
Mods: Never enough...
Cautela Why haven't you checked into rep rehab yet?Cautela Why haven't you checked into rep rehab yet?Cautela Why haven't you checked into rep rehab yet?Cautela Why haven't you checked into rep rehab yet?Cautela Why haven't you checked into rep rehab yet?Cautela Why haven't you checked into rep rehab yet?Cautela Why haven't you checked into rep rehab yet?Cautela Why haven't you checked into rep rehab yet?Cautela Why haven't you checked into rep rehab yet?Cautela Why haven't you checked into rep rehab yet?Cautela Why haven't you checked into rep rehab yet?
Troubleshooting Idle Problems

Do you have erratic, loping, searching, bouncing, or however you'd like to call it, idle problems? Here's a general list of things to do to troubleshoot your idle, focusing mainly on servicing the "FITV" (Fast Idle Thermo Valve). This tutorial assumes you have no CEL (check engine light) codes, you must take care of those first (chances are that's part of the idle problem). Also, if you have a bad thermostat this is the time to install a new one as you need the car to be able to reach normal operating temperature...

If your idle is stable but either too high or low then you need to adjust it with the idle screw, but don't just turn the screw blindly! The correct way to do it is by letting your car warm up (wait until the fan comes on) then, while the engine is running, disconnect the IACV (Idle Air Control Valve) electrical plug behind the intake manifold, then adjust the idle screw to 800rpm. After doing that turn your car off, reconnect the IACV plug, then disconnect the battery for a couple of minutes to reset the ECU because you will have a CEL, doing this will get rid of that CEL. Recconect the battery and your Idle should be at its normal range (usually around 650rpm). Idle control screw location: refer to post #76 (http://www.superhonda.com/forum/3991603-post76.html).

Most of the time, erratic Idle is caused by a disturbance in the vacuum system, the engine will continiously try to compensate for the gain and loss of extra air coming into the intake. When you start your car and the engine idles, air bypasses the throttle plate through a couple of holes, one from the FITV and the other from the IACV. The purpose of the FITV is to let extra air in when the engine is "cold" to help it idle/attain the right A/F ratio; after the engine is at normal operating temperature, hot coolant flowing through a thermostat in the FITV heats up a substance inside it which pushes a little plunger that closes the valve that's letting air through on the other side, at that time the IACV will control the idle. The main difference between both of these systems is that the FITV is mechanically controlled and the IACV is computer controlled (that's why it's connected to the harness).

The first thing you should look for is any apparent leaks from vacuum hoses, bad seals, improperly tightened mating surfaces on the TB (throttle body), IM (intake manifold), etc. If everything checks out move on to the IACV, unbolt the 2 12mm bolts holding it in place then separate it from the IM. It should look like this:

Note the 2 holes in it, the one you are mostly concerned with is the hole with the screen on it, make sure it is not clogged or otherwise obstructed by debris, if it is you can clean it up with carb/intake cleaner. Bolt it back onto the IM and reconnect any hoses or the electrical plug you may have taken off of it.

EDIT: I forgot to mention to also make sure your valves are adjusted to spec. Yes, valve lash (improperly adjusted intake/exhaust valves) can cause erratic idle.

Now we will move on to servicing the FITV. Most of the manuals you read tell you that if you suspect the FITV to be the culprit of your bad idle, you should throw it away and buy a new one... I'll show you how to check and service it so that you don't have to go and spend money unnecessarily on a new FIT valve.

Part I

1. Separate your intake tube from the TB and look inside, you will see 2 holes... the picture below is self explanatory:


2. Now start your car and let it warm up to normal operating temperature (fan comes on), then put your finger in the FITV hole, there should be ZERO to VERY MINIMAL suction:


3. If there is suction after warm up then there is something wrong with the FIT valve, turn the car off and let it cool down.

4. This is where the manuals tell you to change the FIT valve with a new one, but there are actually a couple of things you can do to "fix" it. First things first, this is what the FITV looks like, it's attached to the underside of the TB or in some models it will be attached on the manifold right under the TB and it may have 2 coolant hoses, mine has one on the FITV and one going to the IACV from the TB (channeled through the FITV):


5. Disconnect any coolant hoses, vacuum lines, and electrical connectors that may be in the way of the back of the FITV (make sure you mark them so you know where to reconnect them):


6. Now look at the back of the FIT valve, there is a flat plate held down by 2 screws, you'll be removing this plate:


This is the FITV plate in an exploded view image on a GSR manifold:


7. Due to the limited space/visibility I used a mirror and an elbowed screwdriver to take it off, you can also use an 8mm socket:



8. Inside is the end portion of the springloaded valve, held down by a white plastic piece with 2 slots on either side:


9. This piece is threaded like a screw and sometimes it will unscrew over time, creating too much slack on the spring of the valve and therefore causing a vacuum leak. Screw it back in with any tool that fits the slots (I used the flathead side of my elbowed screwdriver, turning it clockwise):


10. Replace the plate and reconnect everything you had taken off.

11. Repeat the procedure for checking suction at the FITV hole on the TB (Steps 1-3). If there is still a lot of vacuum in the FITV hole, go to "Part II" below.
__________________
"Look out", gaijin with スカイライン

αθεος

Helpful threads: DIY distributor cap/rotor replacement | Got idle problems? CLICK HERE | Honda OBD1 ECU pinouts

Videos: Okinawa undergound racing | Skyline+full exhaust+tunnel
Cautela is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote
Sponsored Links
Advertisement
 
Old 12-12-2005, 12:40 AM   #2 (permalink)
Type-S Member
 
Cautela's Avatar
 
Join Date: Oct 2002
Location: California Dreaming
Posts: 2,159
Car: '94 Integra Ls/vtec-Turbo (now GSR proj), '93 R33 Skyline GTS-25t (Sold), '04 RSX Type-S (new whip)
Mods: Never enough...
Cautela Why haven't you checked into rep rehab yet?Cautela Why haven't you checked into rep rehab yet?Cautela Why haven't you checked into rep rehab yet?Cautela Why haven't you checked into rep rehab yet?Cautela Why haven't you checked into rep rehab yet?Cautela Why haven't you checked into rep rehab yet?Cautela Why haven't you checked into rep rehab yet?Cautela Why haven't you checked into rep rehab yet?Cautela Why haven't you checked into rep rehab yet?Cautela Why haven't you checked into rep rehab yet?Cautela Why haven't you checked into rep rehab yet?
Part II

At this point all there is to do with the FIT valve that's within your capabilities is to check that the plunger inside the FITV thermostat is working properly, and if possible replace with a new plunger.

1. First let the engine cool down, then disconnect the coolant hoses attached to the FITV:


2. There are 3 10mm bolts holding the FITV in place (note I used a mirror so you can see them from underneath):


3. Remove the FITV from the TB:


4. Remove the FITV thermostat housing (held down by 2 phillips screws), be careful not to tear the O ring inside:


5. You should see the thermostat (brass piece) and the springloaded valve recessed inside against the plunger:


6. Now here's the fun part, get a lighter and hold it on the thermostat for about a minute:


7. While looking into the chamber where the plunger is, you should see it slowly pushing the valve closed as it heats up:


I happened to have a spare FITV from another manifold so I was able to swap plunger/thermostat assemblies, I had to swap the plungers as opposed to the whole FITV because the configuration of hoses and bolt pattern was different, but the thermostat/plunger is the same...


8. Unscrew the the thermostat/plunger assembly from the donor FITV with large pliers or arc joint, take care not to damage the assembly too much as it is made from brass (you don't want brass floating around your cooling system):


Compare both plungers. In my case the old plunger was leaking the heat reacting fluid thus not having enough of it to expand and push the plunger all the way out to close the valve completely:


9. Screw the 'new' thermostat/plunger in and tighten with the pliers.

10. Reinstall everything back in and check for suction after the engine is warmed up, you shouldn't have any.

If after all of this you still have suction from the FITV (after engine is warm) you're SOL and need a new FIT valve. If this fixed your FITV but not your erratic idle then you may need a new IACV. Good Luck!


~THE END~
__________________
"Look out", gaijin with スカイライン

αθεος

Helpful threads: DIY distributor cap/rotor replacement | Got idle problems? CLICK HERE | Honda OBD1 ECU pinouts

Videos: Okinawa undergound racing | Skyline+full exhaust+tunnel
Cautela is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote
Old 12-12-2005, 08:04 AM   #3 (permalink)
Dark Wind
 
Join Date: Jan 2005
Location: Newark, DE
Posts: 5,517
Car: 1979 Porsche 911SC, 95 Chevy S-10, 2 1990 Miatas
Mods: Don't you wish you knew
hobie237 has a Rep problemhobie237 has a Rep problemhobie237 has a Rep problemhobie237 has a Rep problemhobie237 has a Rep problemhobie237 has a Rep problemhobie237 has a Rep problemhobie237 has a Rep problemhobie237 has a Rep problemhobie237 has a Rep problemhobie237 has a Rep problem
Very nice... I owe you a rep after 24 hours, since I've given too much out...


THIS SHOULD BE A STICKY
hobie237 is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote
Old 12-12-2005, 12:06 PM   #4 (permalink)
Olde School Ricer
 
Join Date: Apr 2004
Location: N.Y.
Posts: 8,794
Car: 89crx
Mods: built motor, supercharged
yellowrexsi Bow down before me!yellowrexsi Bow down before me!yellowrexsi Bow down before me!yellowrexsi Bow down before me!yellowrexsi Bow down before me!yellowrexsi Bow down before me!yellowrexsi Bow down before me!yellowrexsi Bow down before me!yellowrexsi Bow down before me!yellowrexsi Bow down before me!yellowrexsi Bow down before me!
Quote:
Originally Posted by hobie237
THIS SHOULD BE A STICKY
Yep. The most common problem for a honda
__________________
yellowrexsi is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote
Old 12-12-2005, 12:21 PM   #5 (permalink)
Type-S Member
 
Cautela's Avatar
 
Join Date: Oct 2002
Location: California Dreaming
Posts: 2,159
Car: '94 Integra Ls/vtec-Turbo (now GSR proj), '93 R33 Skyline GTS-25t (Sold), '04 RSX Type-S (new whip)
Mods: Never enough...
Cautela Why haven't you checked into rep rehab yet?Cautela Why haven't you checked into rep rehab yet?Cautela Why haven't you checked into rep rehab yet?Cautela Why haven't you checked into rep rehab yet?Cautela Why haven't you checked into rep rehab yet?Cautela Why haven't you checked into rep rehab yet?Cautela Why haven't you checked into rep rehab yet?Cautela Why haven't you checked into rep rehab yet?Cautela Why haven't you checked into rep rehab yet?Cautela Why haven't you checked into rep rehab yet?Cautela Why haven't you checked into rep rehab yet?
No problem, it just pisses me off that you have to look through all kinds of different resources to find this information, and there are never pictures to illustrate the steps... Since I had to do this procedure recently, I figured why not make it a little easier for people to find it in one place
__________________
"Look out", gaijin with スカイライン

αθεος

Helpful threads: DIY distributor cap/rotor replacement | Got idle problems? CLICK HERE | Honda OBD1 ECU pinouts

Videos: Okinawa undergound racing | Skyline+full exhaust+tunnel
Cautela is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote
Old 12-12-2005, 12:21 PM   #6 (permalink)
Dark Wind
 
Join Date: Jan 2005
Location: Newark, DE
Posts: 5,517
Car: 1979 Porsche 911SC, 95 Chevy S-10, 2 1990 Miatas
Mods: Don't you wish you knew
hobie237 has a Rep problemhobie237 has a Rep problemhobie237 has a Rep problemhobie237 has a Rep problemhobie237 has a Rep problemhobie237 has a Rep problemhobie237 has a Rep problemhobie237 has a Rep problemhobie237 has a Rep problemhobie237 has a Rep problemhobie237 has a Rep problem
Quote:
Originally Posted by yellowrexsi
Yep. The most common problem for a honda

And we get a thread about it what? Twice a week? LOL.

If it's a sticky, it's getting a link in my sig.
hobie237 is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote
Old 12-12-2005, 12:24 PM   #7 (permalink)
Olde School Ricer
 
Join Date: Apr 2004
Location: N.Y.
Posts: 8,794
Car: 89crx
Mods: built motor, supercharged
yellowrexsi Bow down before me!yellowrexsi Bow down before me!yellowrexsi Bow down before me!yellowrexsi Bow down before me!yellowrexsi Bow down before me!yellowrexsi Bow down before me!yellowrexsi Bow down before me!yellowrexsi Bow down before me!yellowrexsi Bow down before me!yellowrexsi Bow down before me!yellowrexsi Bow down before me!
Quote:
Originally Posted by hobie237
And we get a thread about it what? Twice a week? LOL.

If it's a sticky, it's getting a link in my sig.
Very true. Easier to link than explain everytime.
I like it when someone said they searched and didn't find anything.
__________________
yellowrexsi is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote
Old 12-12-2005, 12:24 PM   #8 (permalink)
Type-S Member
 
Cautela's Avatar
 
Join Date: Oct 2002
Location: California Dreaming
Posts: 2,159
Car: '94 Integra Ls/vtec-Turbo (now GSR proj), '93 R33 Skyline GTS-25t (Sold), '04 RSX Type-S (new whip)
Mods: Never enough...
Cautela Why haven't you checked into rep rehab yet?Cautela Why haven't you checked into rep rehab yet?Cautela Why haven't you checked into rep rehab yet?Cautela Why haven't you checked into rep rehab yet?Cautela Why haven't you checked into rep rehab yet?Cautela Why haven't you checked into rep rehab yet?Cautela Why haven't you checked into rep rehab yet?Cautela Why haven't you checked into rep rehab yet?Cautela Why haven't you checked into rep rehab yet?Cautela Why haven't you checked into rep rehab yet?Cautela Why haven't you checked into rep rehab yet?
Quote:
Originally Posted by hobie237
And we get a thread about it what? Twice a week? LOL.

If it's a sticky, it's getting a link in my sig.
True, that's another reason, people are often asking idle related questions...
__________________
"Look out", gaijin with スカイライン

αθεος

Helpful threads: DIY distributor cap/rotor replacement | Got idle problems? CLICK HERE | Honda OBD1 ECU pinouts

Videos: Okinawa undergound racing | Skyline+full exhaust+tunnel
Cautela is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote
Old 12-12-2005, 12:25 PM   #9 (permalink)
Dark Wind
 
Join Date: Jan 2005
Location: Newark, DE
Posts: 5,517
Car: 1979 Porsche 911SC, 95 Chevy S-10, 2 1990 Miatas
Mods: Don't you wish you knew
hobie237 has a Rep problemhobie237 has a Rep problemhobie237 has a Rep problemhobie237 has a Rep problemhobie237 has a Rep problemhobie237 has a Rep problemhobie237 has a Rep problemhobie237 has a Rep problemhobie237 has a Rep problemhobie237 has a Rep problemhobie237 has a Rep problem
Quote:
Originally Posted by yellowrexsi
Very true. Easier to link than explain everytime.
I like it when someone said they searched and didn't find anything.

Yeah. Then they start bashing the search function on the site and you just want to

In fact, the link is going in my sig now.
hobie237 is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote
Old 12-12-2005, 02:10 PM   #10 (permalink)
Ninja Matsume
 
HondaVTEC93's Avatar
 
Join Date: Aug 2004
Location: Pennsylvania
Posts: 3,813
Car: 2006 Honda Civic Ex
Mods:
HondaVTEC93 has a Rep problemHondaVTEC93 has a Rep problemHondaVTEC93 has a Rep problemHondaVTEC93 has a Rep problemHondaVTEC93 has a Rep problemHondaVTEC93 has a Rep problemHondaVTEC93 has a Rep problemHondaVTEC93 has a Rep problemHondaVTEC93 has a Rep problemHondaVTEC93 has a Rep problemHondaVTEC93 has a Rep problem
or air pockets.


very nice write up man that will answer 10,000 questions from people...including myself. rep.
HondaVTEC93 is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote
Old 12-14-2005, 12:59 AM   #11 (permalink)
SuperHonda Member
 
Join Date: Dec 2005
Posts: 115
Car:
Mods:
Repeat_Offender is a glorious beacon of lightRepeat_Offender is a glorious beacon of lightRepeat_Offender is a glorious beacon of lightRepeat_Offender is a glorious beacon of lightRepeat_Offender is a glorious beacon of light
Good info
Repeat_Offender is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote
Old 12-14-2005, 06:48 PM   #12 (permalink)
SH Black Diamond
 
Join Date: Sep 2005
Location: Naperville Illinois
Posts: 440
Car: 1996 Honda Civic EX Coupe
Mods: Painted Side Skirts, AEM Intake, Eibach Pro-Kit Springs, A'PEXi World Sport 2 Exhaust, Holley Header. Magnaflow Cat, Si spoiler, JDM Type-R fornt Lip, Spoon Sports Carbon Mirriors, Projector HID Headlights, Integra GS 15" Rims (Gunmetal), BFGoodrich G-Force Sport Tires, Red Wrincle Painted Valve Cover, Others.
rockintheEKoupe is just really nicerockintheEKoupe is just really nicerockintheEKoupe is just really nicerockintheEKoupe is just really nice
Sticky
__________________
-96 EK Coupe Lackluster Silver: SOLD
-2001 Trans Am WS.6 M6: Arctic White
-2004 S2000: Sazuka Blue


rockintheEKoupe is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote
Old 12-15-2005, 04:38 AM   #13 (permalink)
SH Black Diamond
 
Join Date: Feb 2003
Location: ohio
Posts: 474
Car: 1995 Honda Del Sol S, 1971 pontiac lemans, 1998 Malibu LS
Mods: Name it, engine swap, Rota wheels, Flaken Aziens, AEM intake, headers, hyper medalion full exhaust, lowered, apc reverse indiglo gauge faces pioneer premier headunit, 2 jbl 4.800's amps leading to the Four infinity kappa perfect component 6 1/2 speakers, a 2.800 jbl run tpo 2 infinity perfect 12's and way more fiberglass than I should have done.
sorrow is a rep whoresorrow is a rep whoresorrow is a rep whoresorrow is a rep whoresorrow is a rep whoresorrow is a rep whoresorrow is a rep whoresorrow is a rep whoresorrow is a rep whoresorrow is a rep whoresorrow is a rep whore
yes I like the quality of the shots you took. Should help people out a-lot. Time to give out that rare rare rep. Oh and I say either sticky it or add it to an existing sticky. Either way its going in the archive!
__________________
And the man said: Live fast Die young And Leave a Good looking corpse
sorrow is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote
Old 12-15-2005, 12:42 PM   #14 (permalink)
SH Silver
 
Join Date: Oct 2003
Location: New Jersey
Posts: 229
Car: 1995 Del Sol Si
Mods: Engine Block: B18B1 W/BG. Bearings: Clevite Tri-Metal MB&RB. Oil Pump: Type-R. Underdrive Pully: Forum. Rods: Eagle H-Beam. Pistons: CP-Pistons 10.5:1 Compression. Cylinder Head: B16A Polished. Valve Train: V,S,R Skunk2. Cams: JDM Spec B16A Cams. Intake Manifold: AEBS. Throttle Body: Holly 62mm. Fuel Rail: Stock. Fuel Pressure Regulator: B&M. Intak
NutromiX has a little shameless behaviour in the past
Angry

So what happens when you don't have a Fast Idle Control Valve like with a Skunk2 Throttle Body!
NutromiX is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote
Old 12-15-2005, 01:35 PM   #15 (permalink)
Moderator
 
NationsMostWanted's Avatar
 
Join Date: Feb 2002
Location: City in Cali!
Posts: 20,657
Car: 2008 Infiniti G35S and 2008 Mercedes-Benz C300 Sport
Mods: Taillight Overlays and Magnaflow Exhaust
NationsMostWanted you're still here?NationsMostWanted you're still here?NationsMostWanted you're still here?NationsMostWanted you're still here?NationsMostWanted you're still here?NationsMostWanted you're still here?NationsMostWanted you're still here?NationsMostWanted you're still here?NationsMostWanted you're still here?NationsMostWanted you're still here?NationsMostWanted you're still here?
very well said...
__________________
2008 Infiniti G35 Sedan Blue Slate/Graphite Interior:Sports and Premium Package 5AT, 2008 Mercedes-Benz C300

NationsMostWanted is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote
Sponsored Links
Advertisement
 
Reply


Currently Active Users Viewing This Thread: 3 (0 members and 3 guests)
 
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Powered by vBadvanced CMPS v3.2.2

All times are GMT -7. The time now is 03:20 AM.



Powered by vBulletin®. Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Search Engine Optimization by vBSEO 3.3.2