Search:
Attention Honda Civic Visitor:  Remove this block by logging in above or registering.

Welcome to ClubCivic

Club Civic is an online Honda Civic forum and community for all Honda Civic enthusiasts. Whether you own a Honda Civic Si, Ex, Type R, Dx, Lx, Cx, Dx, Vx, or even a hybrid you will find valuable information and car parts on this site. Take a look around to view Honda Civic discussion; including a photo gallery, maintenance information, tech tips, as well as ways to get better performance from your Honda Civic. Visit the member’s garage to view and rate other member’s Honda Civics. Click here to start viewing the Honda Civic Forums. Before you start posting on this site you will need to register. If you are already registered and not logged in, please login here.

Browse the forums by generation by clicking below or browse all honda civic forums.


Go Back   ClubCivic.com - Honda Civic Forum > Honda Civic Technical > Engine Tech / Drivetrain

Notices

Please SEARCH Before Posting a New Thread. ->
Ready to Post a New Thread/Question? ->  



Rough Idle Troubleshooting

Engine Tech / Drivetrain


Technical forums are exclusively for technical discussions.
Ľ Thread Makers: Thread titles must summarize the technical question or problem, and the first post must include the year, trim, and any mods for your Civic.
Ľ Responding Members:
Limit your posts to helpful responses, and do not tell members to "Go Search", unless you also provide some specific guidance on the technical question or problem.
Ľ All Members: Rude or flaming posts will not be tolerated, though civil debate and disagreement are acceptable.

User Tag List


Reply
 
Thread Tools
Old 12-09-2006, 08:27 PM   #1
kyle10182
NA is Best
 
kyle10182's Avatar
 
Join Date: Sep 2005
Location: East Coast
Age: 27
Posts: 6,572
 
Thanks: 0
Thanked 1 Time in 1 Post
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)

Default Rough Idle Troubleshooting

alright, i was just reading a post about a rough idle. some people seem to think that they are the first honda owners to have this problem. well its a common problem. especially after a swap. well i visit G2IC.com a lot. and they have a lot of useful information on there that can help these problems. im going to copy a post from there that can hopefully help everyone with their idle problems. maybe a mod will even sticky this to keep down on the bad idle threads everyday.

Quote:
Bad Idle Troubleshooting

This is for high and roaming idles but may work for low idles as well.

First, terms:

TB Ė Throttle Body
IM - Intake Manifold
IACV Ė Idle Air Control Valve (also called the Electronic Air Control Valve or EACV)
FITV Ė Fast Idle Thermo Valve
TPS Ė Throttle Position Sensor





I finally got the swap (b18a) in my civic. Unfortunately when I started it up it idled at 3k and then had a hunting idle from 2k to 2500 rpm when it warmed up. I stood over that thing for 3 days, testing and scratching my head. On top of that I did a TON of searching on the h-t, hybrid boards, and on here. I hope what is contained within helps someone. Maybe they wont have to go through as much work as I did.

The idle on our Hondas is a tricky thing. It is controlled by two main sensors: the FITV and the IACV. The FITV is a mechanical valve that is controlled by coolant temperature (there is no ECU plug to it). When the coolant is cold the valve is open and letting air into the IM through a hole in the TB before the throttle plate. This essentially creates a small vacuum leak which in turn lets the motor idle higher than normal (supposed to be around 1500-2k for warming up). As the coolant warms up the valve closes and no longer lets air in through the hole in the throttle body. All the while the IACV, which is ECU controlled, is letting small amounts of air into the IM through another hole in the TB. Any amount of extra air the ECU is not expecting will confuse it and you will get either a high idle or a roaming/hunting/fluctuating idle. On to the troubleshooting.

First things first, donít skip any of these steps. From what I have read (and experienced) usually small dumb things cause these problems so donít overlook anything. Also refer back up to the pictures if need be.

1) Check your vacuum routing. On the underside of your hood there should be a vacuum diagram. If there isnít a diagram under there, there is one in a Helms, Chiltons, or Haynes manual for your car (you should have one of these anyway). Remember, ANY extra air will confuse the ECU. Check for cracked or bad vacuum hoses. If in doubt just replace the hose, they are cheap.

The PCV valve could also be the culprit. Take it out and examine it. If it is cracked it could be causing a vacuum leak. Replace the peice if you arent completely sure it is ok (the helms/chiltons/haynes manuals tell you how to check it).

2) Check to see that your throttle plate is closed all the way. Take your intake off at the TB and check to see that nothing is blocking the plate. If nothing is in the way and it isnít closed all the way, loosen your throttle cable.

3) Check to see if the nuts holding the TB and the IM on are tight, this was the source of my idle problem. If they are loose, tighten them.

4) Bleed your coolant. Some air bubbles may throw the FITV off and keep the valve open.

5) Take the 3 10mm bolts out of the FITV (you donít have to take off the coolant lines). Then take off the 2 8mm bolts off the plate on the back of the FITV. Once the plate is off you will see a white plastic thing, screw that all the way in. This causes a TON of peopleís hunting idle problems (itís a source of a vacuum leak). Put the FITV back on and start the car up. If it still idles bad go on.

6) Clean the IACV screen(s). See Ozís write up elsewhere on G2IC.

7) 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 (I have only read of people doing this, so I donít know exactly how. Also, you will have to keep the engine speed up yourself when the car is cold).

Next cover both holes up with your fingers. The car should sputter and die (or almost die). If it does then the source of your crappy idle is the IACV. Replace it. If you want you can test the IACV. Shut the car off and put + battery voltage to the blk/yel terminal (on the valve) and momentarily touch ground to the blu/yel side. When doing this the valve should click, if it doesnít, replace it.

If, when covering both holes the car still has a high idle, you have a vacuum leak somewhere. Again check the IM and TB nuts. You can spray carb cleaner around those areas and if any gets sucked in (the engine will rev) you have found your leak. Another source of vacuum leaks are where the FITV and IACV connect to the IM. Either replace the gaskets or use silicone gasket sealant.

8) If nothing has worked you should test your TPS. Probe the middle wire on the TPS plug (with the key on but not running, and the plug still connected to the sensor) with the + probe on the volt meter, and the neg probe to ground. You should have .5v with a fully closed throttle plate and 4.8v with it wide open. If the TPS is off, replace it. My TPS was .425v to 4.55v and it idles fine now so I donít know how big the margin of error is. Also, it is pretty rare for these to go bad.

9) If, still, nothing has worked you might want to try a new ECU. This also is very unlikely, but worth a try.

10) If it still idles bad, go through the steps again.

I really really hope this helps someone out. It was a pain to have this mysterious problem and very little info on how to go about troubleshooting it. Comments or suggestions are welcome.
This information comes from Ben Ogle @ G2IC.com.
kyle10182 is offline   Reply With Quote
Old 12-09-2006, 08:31 PM   #2
si-hatch86
undesputed slowhatch
 
si-hatch86's Avatar
 
Join Date: Mar 2006
Location: pasco
Age: 28
Posts: 1,105
 
Thanks: 0
Thanked 0 Times in 0 Posts
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)

Default

no im the only person that has EVER had this problem

good post
__________________
"fighting for peace is like f@cking for virginity"
Quote:
transzex of d-series.org
....only stupid people hydro lock motors....
Quote:
Originally Posted by turbo95eg6
You give your mom "hard rides"...?
ED squad #2
si-hatch86 is offline   Reply With Quote
Old 12-09-2006, 08:51 PM   #3
stealthy
4 Doors For More Whores
 
Join Date: Oct 2003
Location: Ohio
Age: 29
Posts: 7,586
 
Thanks: 0
Thanked 0 Times in 0 Posts
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)

Default

good s***
__________________
--BJ--
- GSR Sedan
- CP 81.5 9:1 Pistons
- Eagle H Beam Rods
- Garrett T3/60-1 .63a/r


stealthy is offline   Reply With Quote
Old 12-09-2006, 09:06 PM   #4
kyle10182
NA is Best
 
kyle10182's Avatar
 
Join Date: Sep 2005
Location: East Coast
Age: 27
Posts: 6,572
 
Thanks: 0
Thanked 1 Time in 1 Post
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)

Default

Quote:
Originally Posted by stealthy
good s***
u should read on g2ic's forced induction forum.
kyle10182 is offline   Reply With Quote
Old 12-10-2006, 07:50 PM   #5
rexman
hondas for life
 
Join Date: Nov 2006
Location: killingly, connecticut
Age: 24
Posts: 389
 
Thanks: 0
Thanked 0 Times in 0 Posts
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)

Default

wow......after all the frustration who wouldve known it was that simple. GOOD post man!!
rexman is offline   Reply With Quote
Old 12-11-2006, 04:52 PM   #6
kyle10182
NA is Best
 
kyle10182's Avatar
 
Join Date: Sep 2005
Location: East Coast
Age: 27
Posts: 6,572
 
Thanks: 0
Thanked 1 Time in 1 Post
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)

Default

i think this should be stickied. to prevent the same questions coming up everyday because of these common problems...
kyle10182 is offline   Reply With Quote
Old 12-11-2006, 05:23 PM   #7
rexman
hondas for life
 
Join Date: Nov 2006
Location: killingly, connecticut
Age: 24
Posts: 389
 
Thanks: 0
Thanked 0 Times in 0 Posts
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)

Default

definatly
rexman is offline   Reply With Quote
Old 12-11-2006, 05:29 PM   #8
kangaroo
..........UPS.........
 
kangaroo's Avatar
 
Join Date: Jan 2004
Location: 92 Civic vx :D
Age: 28
Posts: 2,221
 
Thanks: 0
Thanked 0 Times in 0 Posts
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)

Default

NIce...Nice..Nice....
__________________
kangaroo is offline   Reply With Quote
Old 12-11-2006, 05:34 PM   #9
BuiltforSin
Registered User

 
BuiltforSin's Avatar
 
Join Date: Aug 2004
Location: VA
Age: 26
Posts: 2,456
 
Thanks: 0
Thanked 0 Times in 0 Posts
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)

Default

great post!
__________________
BuiltforSin is offline   Reply With Quote
Old 12-13-2006, 12:58 PM   #10
Rex_89
Registered User
 
Rex_89's Avatar
 
Join Date: Jan 2006
Location: Bay Area Ca.
Age: 28
Posts: 1,071
 
Thanks: 0
Thanked 0 Times in 0 Posts
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)

Default

Good post deifently helped out. I was just wondering. If someones timing is a little off, it could make the idle off too right? I didnt see that mentioned and thats why I was wondering.
__________________
Rex_89 is offline   Reply With Quote
Old 12-13-2006, 04:18 PM   #11
kyle10182
NA is Best
 
kyle10182's Avatar
 
Join Date: Sep 2005
Location: East Coast
Age: 27
Posts: 6,572
 
Thanks: 0
Thanked 1 Time in 1 Post
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)

Default

Quote:
Originally Posted by Rex_89
Good post deifently helped out. I was just wondering. If someones timing is a little off, it could make the idle off too right? I didnt see that mentioned and thats why I was wondering.
u mean cam timing or ignition timing? i dont think ignition timing will have anything to do with it.
kyle10182 is offline   Reply With Quote
Old 12-13-2006, 08:53 PM   #12
Rex_89
Registered User
 
Rex_89's Avatar
 
Join Date: Jan 2006
Location: Bay Area Ca.
Age: 28
Posts: 1,071
 
Thanks: 0
Thanked 0 Times in 0 Posts
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)

Default

No, I mean cam timing. Cant that mess up the idle?
__________________
Rex_89 is offline   Reply With Quote
Old 12-13-2006, 08:56 PM   #13
kyle10182
NA is Best
 
kyle10182's Avatar
 
Join Date: Sep 2005
Location: East Coast
Age: 27
Posts: 6,572
 
Thanks: 0
Thanked 1 Time in 1 Post
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)

Default

i dont think it would. maybe if its off by one tooth. you'll notice alot more then idle if its off by anymore then that...
kyle10182 is offline   Reply With Quote
Old 12-14-2006, 12:26 AM   #14
Rex_89
Registered User
 
Rex_89's Avatar
 
Join Date: Jan 2006
Location: Bay Area Ca.
Age: 28
Posts: 1,071
 
Thanks: 0
Thanked 0 Times in 0 Posts
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)

Default

I think my s***s off a little. Probably like by one tooth. Also sounds like my exhaust is spudering. I dont know but im pretty sure my cams are off by a tooth or so. Hopefully I will try to fix it this weekend.
__________________
Rex_89 is offline   Reply With Quote
Old 12-14-2006, 09:10 PM   #15
kyle10182
NA is Best
 
kyle10182's Avatar
 
Join Date: Sep 2005
Location: East Coast
Age: 27
Posts: 6,572
 
Thanks: 0
Thanked 1 Time in 1 Post
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)

Default

is it in limp mode?
kyle10182 is offline   Reply With Quote
Reply




Bookmarks



Similar Threads
Thread Thread Starter Forum Replies Last Post
Help Troubleshooting Idle/Engine issue for 1997 Civic EX dkanter 6th Generation Honda Civic (1996-2000) 14 11-26-2009 10:19 PM
Rough Idle SleepingSol Engine Tech / Drivetrain 2 06-10-2007 12:21 PM
rough idle --> brake= not rough andre4444 Tech Archive (No Posting) 1 05-31-2007 07:32 PM
Rough idle bilzhorse Tech Archive (No Posting) 2 12-09-2006 11:02 PM
rough idle? NoWayBack91Si Tech Archive (No Posting) 3 07-06-2006 10:56 PM

Thread Tools

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

Forum Jump


All times are GMT -4. The time now is 01:33 AM.


Powered by vBulletin® Version 3.8.5
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
vB.Sponsors
User Alert System provided by Advanced User Tagging v3.1.3 (Lite) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright ģ2007 ClubCivic.com
Best Prices on Aftermarket Car Performance Parts
Freelance Web Design

Store News:

Latest Topics:


Store Specials:

ALL
Unanswered Topics:





Copyright © 2011 ClubCivic.com - ClubCivic.com is in no way affiliated with Honda Motor Company