Teg Tip: Bad Idle Troubleshooting

INFORMATION Articles / Teg Tips
61

HMM, This is similar to my problem. Anyones input on this would be much appreciated. I first discovered this when I went home on my lunch break. I cut my car off and remembered i forgot to get ciggarettes. There was 5 second gap in time between when i cut my car off and then cut it on again. It started up (engine was already at operating temprature) and then rpm’s went down down down, until my car just cut off. THis whole process was about 5-6 second between when i turned my key, to when the engine started up and died. After that, I tried to cut it on again and the engine would just turn over and turn over (this same thing happens if i stall out also). Tried it again, and same thing. I had to wait about 30 seconds with key out of the ignition, to where it would start up again (again, same thing will happen if I stall out)

And this will happen to me all day. Ive tested. But it IS hit and miss. For instance, if i go into a store, im in there for a bit, it wont happen when i try and cut my car on. But like tonight, when i tested it. I cut my car on, let it idle down, then cut it off. Then about 5 seconds later i cut it on again, still didnt happen. Tried that process again, and then it did it.

None of my hoses are cracked and the bolts around my IM and FITV are tight. No air is being sucked from the bottom hole on my TB, but when i plug up both my car DOES stall out/shut off. So I am guessing it is my IACV?? I want to be sure. Its a strange problem. Im going to try the white plug thing tommorow and see if that helps any, Also going to seafoam. What else is something i can try? Intake/Injector cleaner im guessing?

EDIT: Ok, so I just did a test. This is what my RPM’s do.

Running temprature test:

Upon cutting the car on at runing temprature, the rpms from start go like this - 1 notch below 2k for 1 second, down to 1k for 1 second, 1 above 1k for 1 second, then 1 below 1k where it idles at. (this is pretty much a representation of how my car always starts up at running temprature)

I then took the car for a spin. Upon returning to my house, I cut the car off, waited 10 seconds, then cut the car on. RPM’s immediatly went to 2k then car cut off immediatly. No stuttering, no sputtering, just died. I then couldnt cut the car on in about the time it took me to take a piss. when i came back and cut it on, it worked.

I will post my cold-start RPM’s in the morning when i wake up.

62

Mine, even after warmed up, if i’m stopped will sometimes drop to like 200 rpms and seem like its going to die…i’m gonna try the tips out sometime and see what happens

63

mine does the same…after running for whatever amount of time…if i just stop and idle…it jumps up and down and almost stalls but not enough and runs right back up and down once again…gonna have to go through that list

64

Hey ben i came across your page online as well as made oz’s post into a page with active photos, figured this might help–

repair fitv:
http://www.ef-honda.com/ben/Badidle.php

clean iacv:
http://www.darbadar.com/iacvfix1.html

65

My idle fluctuated too until I came across this thread as well as XDEep’s. I’ve had my DA for about 2 months now and the idle has been fluctuating since I bought it. It did the same for the previous owner and he said that all that it need to be fixed was a new IACV.

Well $300 dollars later, it kept doing the same thing. I finally got enough time to get into the FITV and I screwed in the white plastic thing about 20 minutes ago and it’s now running like a champ!

Thank you very much for your informative thread.

66

this is my first post here and i just wanted to say thanks for the write. up i just got my da and it was having this problem when it was given to me. 1/2 hour later its fixed. :ohyeah:

thanks for the help.

67

howdy all

ok, ive had a SHIT idle for a while now and am going to have a little of time soon to check it out.

when just starting its PUURRRRFECT, idles like a champ at like 900-1000K, thats when its warming up in the driveway. ill take it down the road, hit a stop sign and the car dies. it wont even search 9 times out of 10!

so im going to run through the list soon, my question is:

is everything going to be located in relatively the same spots on my B18C?

i recently got a new TPS sensor, and jesus did that help the running rich problem i had.

thats is all…lol

thanks everyone

jeo

68

bump and help peeeeeppppoooooo

p-p-p-please

its hard to pick up chicks when you pull up to them and ur car goes ‘cough, cough cough, diiieeeee’

not that i really pick up chicks since i have a GF lol

you get my drift

help!

thanks
joe

69

Awsome teg tips,

I had a local G2’er down the street show me this,
Fixed my problem, thanks alot,

It sucked stopping at a street light and having people stare at me like they were wondering why I was revving my car over and over,

Even worse when I stopped at one place, and all the contruction workers
would stop working and just stare at me, lol… Most of them with there cigs
just sorta hanging in the mouths, so funny :lol:

Later

70

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 don’t 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 doesn’t, replace it

I did this but when I cover the top hole (IACV)My idle returns to normal and runs really nice like 1000 RPMS, then when I take it off my idle goes back to 1500 RPMS. Can some one explain this, I have a 1991 LS with B16a. Thanks

71

I still have the jumpy idle. I cleaned the IACV. Adjusted the FITV. checked for vac leakes, I dont know whats going on.

72

I just replaced my front left engine mount and my tranny mount. Started her up and she smooth! warmed up quickly, no more fast/jumpy idle. So i would say check your mounts if your having troble still. Bad mounts cause the engine to sit lower. Not good. It cost me like 200 to replce the mounts, but i did all the work myself. So, good luck.

73

bumping this thread, great info that helped fix my car’s wicked idle from hell.

74

wierd…

hum ok i followed each steps, and when i block both holes in the TB, she idle very well ( if i block only the IACV one is does the same) so i thought i had to clean the IACV.
After cleaning it, i put it back in place and started the car and i still have this bouncing idle. And when i block the hole of the IACV in the TB, everything’s fine … and yes my IACV clicks when i put 12v on it

FITV works well i tighten the white plastic and my cold idle is a way better

I’m actually resetting my ecu just for the fun
and im gonna test the TPS but…logically it cant be this because i block the IACV hole and my car runs well…

Oh and im gonna clean my TB and IM with carb cleaner it may help as i cant remember who said to see if it will help

any suggestion?? it will be very appreciated :slight_smile:

Nice writing Ben :rofl:

75

hum…

aw damn it looks dead in here…bah… anyway

I cleaned my intake, injectors, TPS goes from 0.28 to 4.38

But actually i do not have any idle bouncing…it stays at 2100 rpm all the time, cold or not…so i guess i have to adjust my idle screw BUT I never screwed or unscrewed this screw and b4 cleaning all my stuff i was able to rev at 1000 rpm

So im gonna play with that screw soon and see what it does

Peace out guys

76

b18a in 90 LS

is the top port supposed to stop sucking air when the car is warmed up? got the idle back down to ~750 or so after adjusting FITV, but that top port just sucks air big time - almost whistles its so loud with the air cleaner hose assy pulled off. If I put my finger over the top port when warmed up then the engine wants to die

Cleaned the IACV but it wasn’t too bad, just some light black stuff on the screen and the plunger in the other hole had a very light coating of black on it. cleaned it out with carb cleaner (the plunger side really bubbled the carb cleaner for some reason, looked like soda)

get the clicking noise with 12v applied, 12 ohms resistance between the pins and neither pin shorts to ground

any ideas?

77

very useful writeup…helped me out a lot…my problem was my FITV…i then just bought an aftermarket intake manifold and matching throttle body…and that fixed the problem cause there is no provision for the FITV on my aftermarket goodies…but I did have a jumpy idle about 800-1200 rpms…and it was actually my PR3 ecu…plugged in a different one and everything was fine…i took the PR3 ecu and plugged that into a different car w/ the same motor and the idle problem happened again…but now i dont’ have any problems as idleing. i just don’t have the FITV, so when my motor is cold…i still idle at 750 RPMS…haha

78

Nice write up:up: wish it helped me which it didn’t :frowning: I tried everything step by step twice, replaced the IACV twice (cleaned them both) replaced FITV once and screwed in all the way on both still bouncing idle. TB bolts are tighten even replaced too, spray carb cleaner all over the vacuum hose to find anything nothing. I also put my finger in the bottom hole it was still sucking at warm idle? When I put my finger on both hole it dies quickly so I’m still stumped on what is going on with my bouncing idle!! It’s driving me nut and it will do that all day long! Is it possible my ECU is at fault? or am I missing something else? Help me out guys :argh:

Thanks

79

tps voltage is suppost to be at .5v @ closed throttle, & 4.5v @ WOT at the pedal. that surely will affect idle.

90redintegra - you just have a searching idle? check all vacuum lines, check the brake booster line, the check valve, and to check for that, you can spray some carb cleaner around the lines, or anywhere where it may suck in air where a leak is, and it will adjust the idle.

80

90redintegra - another thing, have u checked for voltage @ the idle air control valve? when i was trouble shooting my problem a couple months back, i replaced it twice, and went through everything else, to find that the iacv wasnt even getting power.