crxaddikt

car is 1990 CRX Si with DOHC ZC, and its been running fine recently, and i've never had a high idle or erratic idle problem, its always had a steady idle at 800-900rpm.

i thought i would clean the IACV out good since i've never done it and after reading posts how it improves things better, it was hard to get the 2 hoses disconnected from the IACV, so i had to cut them near the top to get them off, but then afterward, when i was putting the hoses back on, i realised i cut one of the hoses so it was too short, (the hose with the coolant), and was too short to fit back on the IACV, so i had to buy a new hose from autozone.
i went to disconnect the old hose from the end connected to the back of the engine, and coolant started draining out, which i did'nt know was going to happen !
then i put the new hose on so it was tight and put small band-clamps over the ends tightened good, and put water in the radiator since the coolant drained out,

i got the other hose that connects to the IACV on fine since i did'nt cut that one too short, then i tightened the 2 mounting bolts to hold the IACV on and plugged the harness clip back on, and was sure i did everything correctly.

while i was at it, i also cleaned out my throttle body and intake and throttle plate with spray carb cleaner and a rag and i let it dry with the throttle plate held open. (just mentioning it in case had to do with anything)

then i started the car up and i was surprised that it was idling high, it was idling at 2500 rpm and not going down even after letting it warm up ?? at first i just thought it was cause you had to drive it around to burn off any left over carb cleaner and then would idle back to normal, or that maybe it would idle back to normal after resetting the ECU, but neither of those did anything and still idled high.

i drove to autozone and got a gallon of coolant and topped off the radiator, then i drove it around and noticed the idle does start going down while your driving but when you put brake and clutch in when coming to stops, thats when the idle raises back up to 2500, but if you just coast without foot on brake or clutch then it stays lower and calmer.

can anyone think of what this can be ??? cause i can't think of why it would suddenly idle high after cleaning the IACV when before it was idling perfect ? cause if anything, it should of made things better ???, and the hoses don't have holes or cuts in them, the gasket on the IACV looked fine and not cracked or brittle, and i did'nt mess with anything else around the intake manifold, that would affect idle, so i'm confused ???

any help would be cool, thnx

ef_cowboy

You have a vacum leak, Or the throttle cable is hung up. Check the cable to make sure it's coming of its track. Also spray the carb cleaner around the manifold to see for a leak. You'll be able to tell if it changes rpm when spraying. The spot at witch it makes a difference will be the gasket that needs to be changed

crxaddikt

i went out to do the vacuum leak check with the carb cleaner method, but could'nt do it cause i could'nt get the carb cleaner i had to spray, even know there was liquid in there the nozzle was messed up or something, i turned upside down and stuff and took nozzle off and back on but would'nt spray,

and for the throttle cable, do you just mean to make sure the cable moves freely and can lift it up, making sure its not stuck or binding ? cause mines loose and moves freely, what about, do you know if the throttle plate supposed to be lined up perfectly straight while its in the closed position ?, cause seemed like mine was slightly tilted ?

and do you know if bleeding air from coolant has anything to do with it ? someone said that ? thanks for the input, also should i worry about driving it like this ? i mean is'nt it the same as if you revved it up to 2500-3000 rpm while normal driving when shifting ? i just think its embarrassing cause i was at a taco bell drive through and there were all these nice luxery cars around me and i was sitting there helpless with this loud high revving idle, but to me it also seemed like after going on the highway and opening hood that the engine was running a lot hotter or something ? and almost seemed to smell like it was heated more ? (but maybe i'm wrong), but i'm just being carefull and observant cause don't want to mess anything up

wannabegsr

yes bleading air from coolant is a must. Your iacv isnt getting any Coolant so it thinks motor is cold still. I think and u mite have cleaned up some crap that was in the tb so u mite have to adjust the idle down to do that u need to turn car on unplug the iacv and turn the screw on top of the tb i hope that fixes ur problem ohh ya to get the air out of coolant use the bleader screws and jack the front of car high in air with radator cap off with it running i had same problem with my old ls hope that fixes it but wat do i know im an idoit

grog

You should definately burp / bleed the coolant first and go from there.

crxaddikt

why would you say the IACV is'nt getting any coolant ?, would'nt coolant go through that one hose that connects to the IACV thats for the coolant ?, cause when i disconnected that hose from the engine side, i saw all the coolant drain out (which i did'nt know was going to happen), and after putting the new hose i then put water in the radiator, not totally full though, and then went to autozone and got more coolant, then i topped it off with it.

but i will try it if you both say so, but i really never have "bled air from coolant"?, i have only flushed and drained the radiator from the bottom and refilled with new coolant but i'm sure i can figure out how to bleed the air, if its not that complicated, thanks for the input, i will try the idle screw adjust, also am going to spray carb cleaner around and check for vacuum leaks (after buying more carb cleaner), and check throttle cable if stuck and check throttle plate if opening correctly,

and before when i started it, it just idled at 3000rpm steadily, and after warmed up a little it went to 2300 rpm or something, and to 2000rpm, but never any lower, and i did what someone said and unplugged the harness clip going to the IACV while it was running, and it dropped in rpm a little but was still high, like it was at 3000rpm when unplugging it and probably went down to about 2100rpm or so, not sure if that tells me anything or not?, anyways i'll try some more stuff, thnx

RuneRavenX

Adjust your idle with the idle set screw. You should download a manual also. It's idling high because you cleared everything out and there is more airflow. PM me for instructions if you need them. And you have never bled the coolant? That's a must after draining the radiator or flushing the system.


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crxaddikt

i did like a couple of you said and i bled the air from the bleed valve to get air trapped in coolant out, i did it while on the phone with mechanic friend so he can say exactly how to do it, afterwards after coolant was topped off and bleed valve tightened back up, i started it and the idle was still high, maybe just slightly lower but did'nt do much bleeding the air like i was thinking it was.

i tried turning the idle adjusting screw while the IACV plug was unplugged, and i turned it so it would lower the idle, and turned it all the way towards the side that made it low, but it really did'nt lower the idle rpm much at all, but had to try to see if it helped.

then while the car was idling, i was just looking around trying to see anything that might cause the high idle, and i tightened the nut thats on that throttle pulley lever thing (the thing you rev engine by hand with), and i just started to tighten the nut a little bit cause i can see when i turned the nut to the right, the throttle plate in the TB is moving, like the throttle plate looked slightly tilted to me, and when turning that nut, the throttle plate starts getting more straight and vertical, so its lined up, but when i was starting to slowly tighten that nut on the throttle pulley lever, i heard the high idle starting to get lower, and bit by bit i turned it and checked the tach inside, until i got it idling around 900 rpm, which was back to normal.

so i was thinking i fixed the problem at that point, cause it was idling steady at that rpm, and i tightened that nut down good while it was in the position so it would'nt move, so i turned the car off, and went inside for a while, and later that night i was going to go out and work on some other things on my car, and i started it up but it sucked cause it shot right back up to that high idle again ! ! !, around 3000rpm or 2500 ! ! !, so that nice low idle i had it on from turning that nut did'nt hold and stay for some reason ?

oh, i also reset the ecu after turning the idle adjust screw, but did'nt help make idle lower or anything.

the next thing i was going to do was to adjust the throttle cable, i measured the deflection of the cable, and it said to be 10-12mm, and it was more like 7mm, so i did how the steps said, loosening the nut on the left and adjusting the nut on right, so i turned the nut on left of throttle cable towards left to loosen it, and then tightened the nut on the right, going clockwise until it seemed like the throttle cable was getting looser, then i tightened the nuts down good, i went to check and start car up and freaked out, cause it instantly just jumped up to a really high rpm like 4500 rpm or higher !!!!, screaming, and i instantly turned the key off, and so i tried adjusting the throttle cable a different way like tighter and then looser, and both times i went back and started car and it instantly shot up to really high rpm,

so i was confused, cause if i left it the way it was, i could'nt even drive it home (from the car-wash i was at), but then i slowly tightened that nut thats on the throttle pulley lever, towards the right and then the idle started lowering down and i got it down to 1000rpm so its steady, and i had it steady idling for like 15 mins or more while i was doing some other stuff, but then i went leave and go home and i started it and it just started idling high again at 3000 rpm, and did'nt stay at the 1000rpm i had it to for some reason ?, i was thinking maybe the throttle plate is'nt closed all the way or is sort of stuck, and its not staying where you put it with that nut, and just slips back where its tilted more and therefore high rpm and idle ???

so at this point, i don't know what to do next ?, except try some things i read on here, like says to maybe try to adjust the stop screw which is an allen screw under the throttle pulley, and has something to do with the throttle lever and how far it turns back before it stops ?, also i am going to try and clean the throttle body and throttle plate a second time just in case i did'nt do it good enough the first time around, also i'll try and tighten the two little screws on the front of the throttle plate, and maybe put some thin oil on the throttle linkage so it can move more easily and freely, but i have to figure out whats causing this now, cause when i get a new problem on my car, i tend to get obsessed about trying to figure out what it is to fix it.


so if you read all of that, what would you think it sounds like it could be ???

any thoughts ? or stuff i can check or do ? thanks

grog

EDIT: I missed this, yes it needs to shut all to way or it acts like you are on the gas.


is your throttle body sticking? i'm guessing your throttle body is still a bit dirty, which might be causing it to not close all the way. Give it another cleaning, maybe just a clean rag though.

Make sure the throttle body can close all the way on its own.

And did you try to put the idle screw back to where it was?

crxaddikt

i had my air intake off, where i could see the throttle body & throttle plate, and while the car was idling high, i was looking at the throttle plate and i put a wrench on the 12mm nut thats on the throttle pulley lever, and was slowly turning the nut to the right, the nut was mostly tightened already, but when you push the wrench on the nut to the right, the throttle pulley moves a little towards the right, and when you are moving it a little towards the right, you can also see that the throttle plate is moving so its tilting til its straight up and down and lined up, where it looks like its more closed off, and when you are doing that with the nut thats also moving the throttle plate, the idle goes down to a normal rpm range finally, but the only thing is that there is'nt a way i know of to make it so the nut/pulley & throttle plate position stay that way where it is ?? cause all it does is it stays idling low and smooth cause you turned that nut to the right hard, but once you turn car off and start again, it pops out of position and its back how it was and the idle shoots up all high again !!!???

so i wish i knew a way to adjust the throttle plate so it stays more lined up in a more "closed" position, where the nut on the pulley also stays where you tightened it also, cause then it would stay there and the lower idle would stay also.


i am going to clean throttle body & plate a 2nd time and better, just to make sure its not stuck, also i did'nt put the idle screw back how it was yet, actually i usually would never touch or mess with that idle screw, and i just had to try turning it to see if i could lower the idle, but i did and it barely changed the idle much at all, and when i turned the idle screw i turned it so it was all the way in, so it was lowering the rpms, not the other way where it would be coming out and raising the rpms, but i really don't know how to put it back where it was?, i can only guess where it was cause i kind of remember where the angle of the flathead slot was.


just before i was talking on the phone with the guy who made a post just after yours, with user name RuneRavenX, he covered all the details he could think of and he was thinking its probably the gasket on the IACV, even know it might look good, if its an original it can be bad and not sealing good enough, and he said to either buy a new gasket or coat the old gasket with silicone so its good to use again, which i'm about to do, and i talked to my friend who is a mechanic also and he said it might be some sort of spring inside the IACV ? that could be bad ?, so the IACV is not doing its job ? not sure where that is or how to know if good or bad ?, but overall the IACV looked clean and good condition inside and out.


i sprayed carb cleaner around all the hoses and stuff earlier and did'nt hear the rpm raise or anything so nothing pointed to having any type of vacuum leak ?

crxaddikt

thanks for people's replies that helped direct me towards fixing the problem,

got the high idle problem fixed !!, not sure exactly which thing fixed it out of the couple things i did, but first i cleaned out the throttlebody and throttle plate a second time but made sure did really good job saturating it and scrubbing with toothbrush and wiping it out with a rag, then i noticed the throttle pulley lever gets stuck sometimes, like if you push the part of it with the nut on it inward and let go, you can see how it has some play in it where the two parts go together that make up the pulley, and i played around with the nut on the pulley along with adjusting the throttle cable until both seemed like they were operating better, and not too tight or not too loose, and i adjusted those while watching the throttle plate open and close until it seemed like it was more lined up and able to close more, and i lubed up the throttle pulley mechanism and cable real good with WD-40, and seemed to work a little better, and after it seemed like i got it where it was'nt getting stuck anymore, then i removed the IACV and took out the gasket for it and cleaned it off and coated it with Black RTV silicone gasket maker and let it dry a little and then put it back on and tightened the IACV back on the car.

then i started the car up (still doubting it was going to be any different), and sure enough it was idling lower around 1200rpm, and not 2000-3000rpm anymore !!!

so then i drove it around and it was acting fine without surging in idle at all, and i got it up til operating temperature, then parked and unplugged the plug going to the IACV, and turnted the idle screw til it was around a base idle of 650rpm (without a tachometer attached, just visually guessing looking at the tach gauge on the dash), and then i turned car off, plugged IACV plug back in, then reset the ECU pulling the hazard fuse, then started car up and let idle for 15 mins without headlights or a/c on, not touching anything at all, and then turned car off and turned immediateliy back on and let idle, and the idle was back to where it supposed to be at around 800-900rpm cause the ECU automatically set it there after resetting the ECU and everything.

and so it drove perfect with a steady, low idle that did'nt surge or have any jerkiness to it or anything, and did'nt bog down or raise up, just stayed where it should be and was easier when stopping and starting at little stoplights, able to pull away smoothly without having to rev it up or anything.