Doodoo

I hope this topic will help alot of you out.

This fix is mainly for 94-up manifolds and TBs. But you can take some of this knowledge and apply it. I know nothing about dashpots, I hate those things....
You don't have to follow this order, its just one way to go about diagnosing the problem.

I just went through the whole crappy up and down, up and down idle woes. I know this has been covered but topics are everywhere, and fixes are all over.
So before you spend alot of money I have a few things you can check.

1. Make sure your coolant system is fairly bubble free. Idle the motor with the radiator cap off until the cooling fan comes on, this is when the thermostat opens.

2. Check for any codes stored in your ECU. I know 14 is IACV(EACV). If you have this code you may need to change out the IACV(EACV).

3. Check for any cracked hoses or loose clamps.

4. Turn the motor on and remove the 2 pin plug from the IACV(EACV). *WARNING Do not touch anything electrical when removing this plug. I touched my distributor and received 1.1 Gigawatts of electricity through my body.*
This should stabilize idle. If it does, Step 5. If it does not, Step 6.

5. Remove the IACV(EACV) from the rear of the intake manifold. Make sure the rubber gasket is not flat. Hose the valve down with Carb Cleaner. Put it back on and see if this fixed the problem. If not, Step 6.

6. Take your intake off at the throttle body. Start the car and plug the lower hole on the left of the butterfly. You might be able to hear the vacuum leaking out(hissing loudly). If this stabilizes idle, Step 7.

7. If you do step 6 and idle stablizes you have to adjust your Fast Idle Thermo Valve(FITV). It has no code as it is mechanical. The easiest way is the remove your throttle body and then remove the FITV from the bottom(3 bolts). Remove the brass cap on the end held on by 2 phillips head screws. There should be a plunger that you can push in and out. What needs to be done is the ring around the plunger needs to be screwed in, clockwise. *I am not sure how far in it needs to be screwed* I do know that when you look at the valve from the top, the ring you screw in should NOT cover the access hole to the TB. Put it all back together and try again.

8. If Step 7 doesn't work then you still may have a bad IACV(EACV). They don't always throw a code... Rule out everything else first before you buy a new one. Or exchange it for a known good unit.

9. You can also try:
- Cleaning entire throttle body with Carb Cleaner.
- Change TB gasket
- Change rubber O-rings around MAP sensor and TB components. (This helps)

10. If you still have problems then you got problems. Try to spray Carb Cleaner into the TB while running. If this fixes your idle problem then you have a leak somewhere.

I have a B18B so a price run down is like this:
IACV - locally $180(rip) online- around $123
FITV- locally $$$ online - around $60.00
Assorted rubber o-rings - avg. $2.00ea.
source: acuraautomotiveparts.net

I have been working on this for about a week and I finally fixed mine last night. FITV was WAY off. Now she idles like a sleeping bear.
If you have anything to add please do.

Mods: Any chance I can get a sticky?


[Modified by Doodoo, 9:41 AM 11/26/2002]


[Modified by Doodoo, 1:49 PM 11/26/2002]

Doodoo

Check it peoples.

Perfectionist

Hey there! Nice job!! The only other things to add would be to make sure the TPS is at spec, about 0.45 volts, at closed throttle, and that the idle stop diaghram is pulling in with vacuum. If all the vacuum hoses are in good shape, your proceedure should fix most of the idle hunting problems out there.

bitzbp

Wow I just found this thread and boy this answers ALOT of my questions thanks

SteveeeO

something I didn't see that fixed mine was the spark plugs / wires... My idle was going up and down from 500-1500 constantly, I changed out the plugs and wires - fixed it right away!

dannyto

i'm a very sick patient w/ idle problem. pls help.

first, does my car have FITV? it's 99-00 si b16a2 or a3.. not sure.

1) when i let the car sit for awhile, idle will raise back up to 1500. then if i give a little gas and hold it... the car will makes "woo -woo- woo- woo" intead of "woooooo" and of course rpm will jump up and down up and down.

2). when the problem is not happening.. coz no. 1 problem only happen once in awhile. the car will do fine.. but when it comes to light.. and i shift to neutral. and let the car row until stop, the idle needle will drop all the way down to a certain point like... 630 rpm .. then raise back up to 750-850 rpm.

I have replaced IAVC, spark plugs and wires, ditributor rotor and caps, drain coolent. I also have VAFC, bored throttle body 2 years ago, I/H/E.

THe other day, i have tried to unplugged the throttle body posiition sensor when the car was having problem.. the car ran fine.... but the ECU is not showing me any code except idling system error or something. no IAVC.

u seem very knowledgable. hope u can help

Thanks

fonkernuckle

iTrader: (5)

doodoo you are the ****, thanks

Hayce

Cheers.. I joined the forum initally to fix this idle problem. My first honda it had me buggered Turned out to be a missing TB bolt and slightly dodgy IACV.
The FITV was shown the door by previous owner.

longuyen88

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by dannyto &raquo;</TD></TR><TR><TD CLASS="quote">i'm a very sick patient w/ idle problem. pls help.

first, does my car have FITV? it's 99-00 si b16a2 or a3.. not sure.

1) when i let the car sit for awhile, idle will raise back up to 1500. then if i give a little gas and hold it... the car will makes "woo -woo- woo- woo" intead of "woooooo" and of course rpm will jump up and down up and down.

2). when the problem is not happening.. coz no. 1 problem only happen once in awhile. the car will do fine.. but when it comes to light.. and i shift to neutral. and let the car row until stop, the idle needle will drop all the way down to a certain point like... 630 rpm .. then raise back up to 750-850 rpm.

I have replaced IAVC, spark plugs and wires, ditributor rotor and caps, drain coolent. I also have VAFC, bored throttle body 2 years ago, I/H/E.

THe other day, i have tried to unplugged the throttle body posiition sensor when the car was having problem.. the car ran fine.... but the ECU is not showing me any code except idling system error or something. no IAVC.

u seem very knowledgable. hope u can help

Thanks</TD></TR></TABLE>

anyone have a solution to this problem? I have the same problem :-\

sleepster

I gots same problem.

Jaydium

i have the same problem... i have a d16z6...replaced throttle body gasket, has had 2 different iacvalves on, new intake manifold gasket, there are no vacuum leaks, no air in the coolant, 2 diff throttle bodies. and im still getting a surging idle. its really annoying sitting at a stop light going wooo-buhhhhh- woooooo-buhhhhh...the screens on the iacv have also been cleaned....what the hell is going on here? no check engine lights nothing....when i unplug the iacv plug, its got a bounce idle (from like 900-1100) real fast repeditive idle. almost like a bubbling sound. HELP ME

longuyen88

I have a cel, p0505...

It seems that the engine only bogs when the cel comes on. I've tried 3 different iac, and it still have a weird idle. I've also replaced the throttle body gasket, no luck. I've searched for vaccuum leaks, no luck. I put honda bond on the oring of the iac, no luck. Running out of ideas here.

Jaydium

try replacing the FIT valve (fast idle thermo valve) which is located underneath the throttle body...i did that to mine, and thats what stopped the annoying idle...good luck man

Surubasi00

I finally fixed my hunting Idle,

The reason mine was surging back and forth is because I replaced my intake manifold with a Type R mani.
When i replaced the coolant lines that connect the coolant pipe on the back of the motor and the coolant line that connects to the throttle body, there was no coolant in them, They stayed this way because of some odd vacuum and the air trapped there wouldn't allow any coolant to pass

I took of the IACV, cleaned the **** out of it, took off the hoses and plugged the one to the coolant pipe with a bolt

Then I took the radiator cap off ( i don't know if it helps or not ) and used a turkey baster to suck fluid into the hose that comes off of the throttle body

It turns out that there was no coolant at all from the thermostat housing, all the way thru the throttle body and to the IACV, it was some fluke thing, but i sucked fluid in the hoses, put the hoses back on the IACV, filled a little bit of the radiator (lost some antifreeze before i could get the hose capped)

started the car and waited until it got hot, slowly but surely the bubbles came out of the radiator fill and once the car got hot, the hunting idle stopped.

I put the cap back on the radiator, and voila,I was done, it took me about 30 minutes to do.

It's been fine for a while now, the only thing I get is a sudden jump in RPM when i start the car and sometimes when i come to a quick stop, still have to diagnose that


Hope that helps,

Dave

longuyen88

i just replaced my car with an itr manifold and the idle problem appeared. so im gonna try your method. I hope it works for me! thanks

magikbean562

ttt cause this is some helpful ****

classicsam

Your instructions are great. I found one more thing that actually worked after I replaced the IACV without success (after following your step-by-step). I found the FITV coolant chamber clogged with old catalized coolant. I cleaned this out and everything is great for 3 weeks now. I took the old IACV apart and found the same gunk in the water chamber. Here is my suggestion for a first check. Unhook the 1/4 inch coolant line that enters the front of the FITV just below the throttle body. Spray radiator flush (or you can use brake clean) into the nipple, then use air blower to blow compressed air into opening. This will push the gunk through the FITV on to and through the IACV. You can also remove the cover on both FITV & IACV that has the hose nipples and clean it manually but this requires removing both. I got to this solution when I realized that no coolant came out when I removed the hose from the IACV. Hose was dry. Worth a try.

h22crxsi

very good info!

allmotorhorizon

the iacv is something that can be cleaned it is usually dirty. i usually check it by having the engine on and putting my finger to block the port for it. if that is not the problem then you have a intake mani leak. usually check what you just installed in that vicinity. i usually spray carb cleaner to check for mani leak

techsupport

This is a great post with quite a few troubleshooting tips to solve surging idle issues. Does anyone know how to solve a hunting idle when the problem seems to be the fast idle thermal valve but the throttle body is a Scat 2 Alpha, with no external FITV?