Fix your stumbling idle in your KA

[borohingacoupe]

So for the past few months my car would idle normally until it came up to operating temps, then it would stumble, idle rough, and die, if the car was in neutral or i had the clutch in. I searched on here and couldn't really find anything that helped me out. I called a local shop , McKinney Motorsports (http://www.mckinneymotorsports.com/) and they gave me the best advice. Now through pictures and text I hope this helps anyone else out there struggling with the idle on their KA.

First the main cause of the idle issue is a dirty IAC valve.
http://www.we-todd-did-racing.com/wetoddimage.wtdr/wMTE1NjE4NjZzNDEzZGZkMzF5NTQx.jpg

It's tucked under the intake manifold near the fire wall. Very hard to get at and expensive if you take it to a shop to get it fixed. But it doesn't need to be replaced, you can fix your nasty idle issues for less then $10! Here's how...

Get a bottle of Intake cleaner, not carb cleaner, intake cleaner.

See this hose:
http://www.we-todd-did-racing.com/wetoddimage.wtdr/wMTE1NjE4NTZzNDEzZGZkMzF5NTQx.jpg
The bigger one on the right goes from your intake to the IAC valve. If you pull it off while your car is running it will die after a second or two. When your car is off, pull the hose off but leave it still on the nipple enough to seal. Go start your car and then come and using one hand pull the hose off and with the other hand keep your idle up by opening the throttle. With your now free hand get the bottle of intake cleaner and spray some of it into the IAC tube. The car will stumble but make sure to keep it from dieing or you will have to put the tube back on and start the process all over again. Repeat this process several times, I used about half the can. Re-install the tube and take the car for a drive! I drove for about 20 minutes and everything was fine. I did this about a month ago and still have no idle problems.

Hope this helps, let me know if you need more instructions or pictures.

Matt

[skiboard06]

wow thank you for that i have been having all sorts of issues with my idle like that, i will do this tonight. to clarify it is the larger hose on the right and you dont need to do anything with the smaller vaccum hose. So you take it off on the intake side and leave the hose still attached on the engine side while u spray down the hose? thanks

[borohingacoupe]

you got it right. good luck!

[JigokuZ]

I don't have a stumb idle problem.. but I do have a high idle problem... know any way to fix that...

[nsn240]

I don't have a stumb idle problem.. but I do have a high idle problem... know any way to fix that...

tps


so... after this cleaner goes through the aicv... it goes into your engine. I cant imagine its that bad for it though.

[JigokuZ]

thanks... if this trick doesn't work.. try replacing your ECT...

[aznpoopy]

so... after this cleaner goes through the aicv... it goes into your engine. I cant imagine its that bad for it though.

throttle cleaner is pretty much *meant* to be used in this way. you spray it through the throttle body as the engine is running. so unless it's not meant for standard piston engines, its fine. usually there is a hefty warning saying it can't be used on rotaries only.

[DRFT]

does this method apply to sohc too?

[borohingacoupe]

does this method apply to sohc too?

Sorry dude, I don't know. Never worked on a SOHC before. I just know it worked for me on my car.

[aznpoopy]

i don't see why it wouldn't, although i never worked on an SOHC either.

the general principle is the same... spray it into your intake manifold. it's not just to clean out the iacv, but the manifold in general.

[skiboard06]

i did this today and it worked awesome helped my idle a ton thanks a bunch

[outerheaven2k4]

I had the same problem on the KA24E, but i was silly and took off the whole thing without buying a gasket to replace it LOL. I found out however, this method would work and wished I did it.

On the SOHC-
Locate the idle adjust screw
Unscrew completely, be sure to apply some pressure on the screw while unscrewing, there's a spring, dont lose it.
Spray your favorite cleaner in there
Replace screw and adjust your idle back to normal

WOOT
^_^

[Milky6]

sorry to bring a thread back.. but where is the idle adjust screw?

[PF_Doom]

sorry to bring a thread back.. but where is the idle adjust screw?

+1
_____________________________________________

[TipStylez]

Thanks alot for posting this!...

[aznpoopy]

+1

get an fsm...

http://i10.photobucket.com/albums/a104/kirinpoopy/OMG.jpg

[punxva]

good thread, but it'll come back eventually, your best bet is to actually order the gasket from nissan, and take it off of your manifold, its not too hard just 4 bolts and a few plugs, then take some carb cleaner and spray it out throughly, and that'll fix it for longer, but remember that it'll come back after time, it's just like washing your car, it'll always get dirty again.

[Bigballin]

sorry to bring this up but a friend of mind gave me some completely fucked up info. instead of not using carb cleaner i did. and now the car wont start. anyway to flush this out.

[mrmephistopheles]

take your plugs out, clean them off and try again.

[Bigballin]

take your plugs out, clean them off and try again.

so i tried this and still no luck. maybe yall can add this incase something similar happens to someone else.
so far this is what i have tried.
1.just try starting the car regularly
2.waiting a few hours to see if the carb cleaner dissolved (turned into days)
3.pulled the wires from the injectors, then tried starting the car
4.pulled the fuse for the fuel pump, took off gas cap and removed spark plugs, started the car, then put everything back. still no start. also tried to jump start my car thinking it could be the battery didnt work either.

i still think the battery may be drained, ill have to check that out tomorrow. other than that all i hear is the starter and my exhaust making little "puff" noises. i want to throw my POS off a mountain.

[aznpoopy]

carb cleaner shouldn't fuck your shit up.

what exactly did you do?

the only thing you have to worry about it keeping the car running while you do it, so it burns it off as you spray it.

[Bigballin]

carb cleaner shouldn't fuck your shit up.

what exactly did you do?

the only thing you have to worry about it keeping the car running while you do it, so it burns it off as you spray it.

thats where i fucked up on. :( wasnt quick enough and the car quit before i could pull the throttle

[aznpoopy]

damn that sucks.

i would pull off the whole intake manifold and clean it out real good. clean out the iacv as well. consider it a chance to really clean up your whole intake tract. taking it out isnt that bad if you have extension and swivel head sockets.

you could even take this chance to replace all the rubber hoses, knock sensor, or even delete emissions... (ka-t.org has a write up on that iirc)

the other option is to just let it air out and pray... XD

at any rate, good luck!

[Bigballin]

damnit! is there anything else i can do other than take the whole manifold off? shit maybe replace the spark plugs

[Fluxypoo]

I drive an auto 240sx, and i was experiencing these EXACT same problems while the car was in Drive. If it was in Nuetral or park it would idle fine. But if i was at a stop light and had my foot on the brake, the car would stumble and go from 700-500 RPM very quickly and the entire car would shake it was hesitating so bad. I bought the intake cleaner after reading this post. The first time i sprayed some into the tube i used a little less than half the bottle. I didnt notice ANY difference, in fact, the problem seemed to be a little WORSE than before i put any in. I drove the car for about 1.5 weeks. Today i decided to put more in, and see if helped any. I did a second application, reducing the bottle to a little over 1/4 left. So far my idle is good, and hasnt been stumbling since i put it in. Hopefully my car stays like this :) definitely a good maintenance thing to do. :werd:

[sittinsideways]

I drive an auto 240sx, and i was experiencing these EXACT same problems while the car was in Drive. If it was in Nuetral or park it would idle fine. But if i was at a stop light and had my foot on the brake, the car would stumble and go from 700-500 RPM very quickly and the entire car would shake it was hesitating so bad. I bought the intake cleaner after reading this post. The first time i sprayed some into the tube i used a little less than half the bottle. I didnt notice ANY difference, in fact, the problem seemed to be a little WORSE than before i put any in. I drove the car for about 1.5 weeks. Today i decided to put more in, and see if helped any. I did a second application, reducing the bottle to a little over 1/4 left. So far my idle is good, and hasnt been stumbling since i put it in. Hopefully my car stays like this :) definitely a good maintenance thing to do. :werd:

ive had the same problem. i changed my oil and it went away. now it is starting to come back. like when i start it i have to give it some gas if its not warm already. i checked the oil and its low, so i have to fill her back up. I also have to find where it is all going. my guess is a pinched gasget/seal=blowby. i could b wrong and probably am, i dont know all that much. if anyone has any suggestions as to how to fix that problem that would be nice

edit: i have not tried cleaning out the iav valve like mentioned above

[DrifteRs13]

Holy shit this thred helps me so much, hah this ia a dedicated 240er lol

[Dream240]

Holy shit this thred helps me so much, hah this ia a dedicated 240er lol

So did this help you solve your running problems you were having? Are you still shooting flames? Did you ever check the timing?

[S14DB]

carb cleaner shouldn't fuck your shit up.

what exactly did you do?

the only thing you have to worry about it keeping the car running while you do it, so it burns it off as you spray it.
Carb cleaner can eat the IACV from the inside out. Many are chlorinated and love rubber and plastic. Why you look for throttle body cleaner.

[ESone3]

anyone know if this works for an SR?

[S14DB]

anyone know if this works for an SR?
Yes, same hose on the cold pipe.

[DrifteRs13]

timing was righ and the flames are gone thanks, but i just need to do the intake cleaning thing, how long until i see a dif are will ir be like a mirical and just be gona once i put it in there

[Dream240]

timing was righ and the flames are gone thanks, but i just need to do the intake cleaning thing, how long until i see a dif are will ir be like a mirical and just be gona once i put it in there

If you use about 1/2 can as suggested it should clear up on your next drive out. Just make sure your putting the cleaner in as it's running with the throttle open a little.

GL

[ms!3]

you can always just loosen the idle adjuster too. sure cleaning it is good but if you want to get to the parts store to get intake cleaner without youre car dieing at stop lights just loosen the screw.

[illvialuver]

will this work with a ka-t?

[DrifteRs13]

no, dont use for superchared or turbocharged engines, i just did it asnd used half a can and didnt do anything. would the timing have anythign to do wiht it, i never got it timed i just put my new exhause on there thinking it might be no back pressure?

[Dream240]

no, dont use for superchared or turbocharged engines, i just did it asnd used half a can and didnt do anything. would the timing have anythign to do wiht it, i never got it timed i just put my new exhause on there thinking it might be no back pressure?

Wait wait, I thought you just said:

timing was righ and the flames are gone thanks,

I'm not sure if you mean "right" or "high" So did you or did you not check and adjust timing as needed?

You could try using the WHOLE can, maybe yours is just really dirty. Did you put the cleaner in the right hose? The second one from the left, the bigger of the two.

And Drifter.....could you please take the extra 30 seconds and make your posts more gramatically correct? I'm having a hard time understanding you. Thanks. :bigok:

[tachikoma]

I would like to post that I tried this, and it hasn't realy fixed my stumbling idle. I honestly am at a loss here.

I have new spark plugs, cleaned intake & manifold (didn't take it apart, just with the intake cleaner), adjusted timing so its perfect. I followed directions here and cleaned that tube through, but I dont know. Anyone have any ideas?

It's a 96 btw, and it doesn't die at idle, it just stumbles around causing the car to shake lightly, its just annoying really. It accelerates beautifully, its just when its sitting still.

[Dream240]

I found another problem about a week ago, there's a vaccumm line that plugs into the underside of the throttle body. It's only about 5 inches long but it goes to the idle control system. Replace that hose with a new piece from autozone. I found mine to be plugged up at the elbow portion. I replaced it and voila!! no more stumbling idle. Worth a try.

Also when you pull it out, just blow into it. How much air is going through? Mine was completely clogged. I'm currently in the process of changing out ALL the old vaccumm line from my engine bay, there's alot... :(

[tachikoma]

I found another problem about a week ago, there's a vaccumm line that plugs into the underside of the throttle body. It's only about 5 inches long but it goes to the idle control system. Replace that hose with a new piece from autozone. I found mine to be plugged up at the elbow portion. I replaced it and voila!! no more stumbling idle. Worth a try.

Also when you pull it out, just blow into it. How much air is going through? Mine was completely clogged. I'm currently in the process of changing out ALL the old vaccumm line from my engine bay, there's alot... :(
Does this require taking apart the intake manifold?

[Dream240]

no...

Just go to the throttle body and feel the underside of it near the butterfly. You can feel and see the hose. Just work that little shit off and go get some new hose. Best to do it while the engine is cold.

[tachikoma]

no...

Just go to the throttle body and feel the underside of it near the butterfly. You can feel and see the hose. Just work that little shit off and go get some new hose. Best to do it while the engine is cold.
Great I'll check that next.

I really should just take apart the manifold so I can access all the EGR stuff behind it to make sure that's all ok, as well as other vacuum lines. But I'm to busy lately :(

[Blackhat]

This would work on a SOHC also. Just make sure your A/C is off and the car is warmed up first. I imagine that would apply to the DOHC as well. You have 3 idle control valves connected to that hose you're spraying cleaner in. They are:

Air Regulator: Just for cold start idle. When the Fuel Pump comes on so does this valve. When it heats itself up the whole way it closes the valve.

FICD: When your A/C compressor kicks on this valve opens.

AAC: This is the valve you're most likely trying to clean. This is the PWM valve your ECU controls to maintain idle RPM. There's a spring in this part of the assembly that you need to keep fairly clean.

Hope this helped someone!

[s13gold]

ohhhhh......good one...thanks man!

[Blackhat]

Oh, and the hoses that connect to the Throttle body on the SOHC are coolant hoses. I can't speak for the DOHC, but I would think they are the same thing. I've been told it's so the throttle body doesn't freeze up during cold weather.

[redsuns3838]

I find it to clean the AICV better if I just take mine off, and clean it with carb cleaner, re-gasket and re-install. THat way I can really get in there and spray carb cleaner up close and get rid of everything. sometimes I let it soak in there for 10 -15 minutes.

[Dream240]

Oh, and the hoses that connect to the Throttle body on the SOHC are coolant hoses. I can't speak for the DOHC, but I would think they are the same thing. I've been told it's so the throttle body doesn't freeze up during cold weather.

You're thinking of a separate hose, the one that loops into the throttle housing and back out and goes into the upper manifold. The vaccumm line is the 3/8" (i think) line that goes into the throttle body directly under the butterfly. Stand over your passenger fender and you'll see the hose sticking out there. It's easier to access by removing the intake piping section that goes into the throttle body.

Wish i had a pic......

[tachikoma]

Baaaahhhh.

Well after a day or two of fooling around and tweaking everything, it turned out to be my cylinder 4 spark plug.

My friend I put this car together, and he was responsbile for the spark plugs at the time. I was cleaning the throttle body while he installed the plugs. Apparently the 4th one got bent (so the gap was screwed up) and he didnt notice and installed it anyways, hahaha. Thus causing my shaking and stumbling at idle.

Note: he also installed the wrong brand, but that's another story.

So, I have NGK V-Power coppers in there now and it's haulin ass and idling perfect! :D

[zugoi]

I had the same problem on the KA24E, but i was silly and took off the whole thing without buying a gasket to replace it LOL. I found out however, this method would work and wished I did it.

On the SOHC-
Locate the idle adjust screw
Unscrew completely, be sure to apply some pressure on the screw while unscrewing, there's a spring, dont lose it.
Spray your favorite cleaner in there
Replace screw and adjust your idle back to normal

WOOT
^_^

I remember reading in ALdata that you shouldnt mess with the idle screw until you unplug the Tps. If you do you can confuse the ecu which will throw your idle off. Something like that.

[Dream240]

I remember reading in ALdata that you shouldnt mess with the idle screw until you unplug the Tps. If you do you can confuse the ecu which will throw your idle off. Something like that.

Correct-a-mundo...

But first be sure you have your timing set at 20 degrees BTDC (KADE), THEN proceed to set idle. If your timing is off, it will affect your idle.

[santacruisin]

I have a problem with my IACV but its the opposite of everyone. The car idles ok (rough b/c of cams) but my problem is that the car stays at wide open throttle when I put the clutch in to shift gears. If I rev to 5K rpm or more air is still rushing in the engine through the IACV because it is still open and the car bounces of the rev limiter. I just got the car back from the mechanic and he says it must be the IACV because its HUGE in the SR compared to other engines and thats the only place besides the throttle where air can get in. No vacuum leaks.

So is it possible that the IACV is so dirty that it is actually sticking open instead of shut? I searched and it no one else seems to have this problem.

[SlidewayzS14]

wait, cant all this hassel of pulling tubes and holding up the throttle be taken away by taking off the filter on the intake, have a friend hold the revs at like 2k and just spray the into the now wide open intake?

[Dream240]

yeah sure if you like wasting 3 cans of cleaner to do the job that should take only one.

You're getting a more concentrated dose of cleaner if you pull the IACV intake tube and spray in there. It's not that hard really, should take LESS time than pulling the intake filter off, plus you're not getting cleaner on your MAF and possibly damaging it. Those things are touchy.

[supreme_1]

This would work on a SOHC also. Just make sure your A/C is off and the car is warmed up first. I imagine that would apply to the DOHC as well. You have 3 idle control valves connected to that hose you're spraying cleaner in. They are:

Air Regulator: Just for cold start idle. When the Fuel Pump comes on so does this valve. When it heats itself up the whole way it closes the valve.

FICD: When your A/C compressor kicks on this valve opens.

AAC: This is the valve you're most likely trying to clean. This is the PWM valve your ECU controls to maintain idle RPM. There's a spring in this part of the assembly that you need to keep fairly clean.

Hope this helped someone!

since the AAC is the thing which you are trying to clean would taking off the iacv and cleaning it be a waste of time? where exactly is the iacv located?

[whomiked]

The small line to the left of it, what does it go to? The nipple from my intake broke off and I can't hook that line up. Should I plug the line, leave it free, do I need to get a new intake now?

[thedecapitator]

tps


so... after this cleaner goes through the aicv... it goes into your engine. I cant imagine its that bad for it though.


what does tps mean?

[whomiked]

what does tps mean?

Throttle Position Sensor

[Tearlessj]

Anyone have a pic of the hose?

[KA-T_240]

The house that you put stuff in to clean the IACV? Its one of the like 2 big hoses that goes into the stock intake. One goes to your VC, the other goes to your IACV

[Champz]

sorry to bring up this tread again, but can some1 verify which hose it is? theres 2 hose on the intake, is it the small one or big one?

a picture if possible

thanks

[SHIFT__Nismo]

Yeah, sorry to revive this thread, but the original photos aren't working no more, does anyone have photos to confirm for this?


Thanks

[surreybc]

http://forums.nicoclub.com/zerothread?id=254278

cleaning the iacv is one helpful thing. my idle still plummets to 500 rpm when i depress the clutch. seems to be intermittent. my iacv didnt have a gasket. i have seen people selling a gasket for it but i doubt if it needs ones. but not sure. wish there was a complete explanation of the idle system. tried to buy a new iacv but they sent me one with different plugs to mine. so the 1991 is different. amazing how little info is in these forums.

[SHIFT__Nismo]

They thanks for the link, but most of that is pertaining to the S13, I need it for the S14 still.

[Phlip]

Shouldn't be that different

[SHIFT__Nismo]

Well the reason I say that is, in one of the articles, it suggests that removing the IAC valve is "easy", on the S14, my s14 anyways, it's clearly not.

What I'd like to see is the instruction and photos, on how I can clean this thing without having to remove the IAC. I want to be able to confirm which hose I can spray into, to clean it.

Thanks for any help though.

[surreybc]

s13 and s14 have the same engine. sorry but it doesnt get anymore simple or explicithttp://img178.imageshack.us/img178/2762/rearsideuh0.jpg (http://imageshack.us)




http://img178.imageshack.us/img178/2762/rearsideuh0.th.jpg (http://img178.imageshack.us/my.php?image=rearsideuh0.jpg)

[SHIFT__Nismo]

That photo definitely helps, I know which hose now runs to it from the front.

This thing is between the firewall and the intake manifold. On my S14, it's a tight sqeeze because I'd also have the ABS to contend with.

Thanks for the photo once again.

[Zaffie]

thanks... if this trick doesn't work.. try replacing your ECT...

hey man, i cleaned my idle valve well, it ran excellent for about a week then still stalls on me at times, i checked all my vaccum hoses, im going to replace the ECT like u said, but i dont really get how that sensor would play a roll in stalling, please explain. peace

[Bigsyke]

hey man, i cleaned my idle valve well, it ran excellent for about a week then still stalls on me at times, i checked all my vaccum hoses, im going to replace the ECT like u said, but i dont really get how that sensor would play a roll in stalling, please explain. peace


Defective ECT means pinging/f*ed up timing and horrible a/f ratios.

[Devens240]

all i can see for the pics on the first page is red X's :-(

[s13pignose]

I hate to bring this thread from dead, but also hate to make a new one and then get told to search when I already read this thread...but like said the pix aren't working. I no longer have stock intake, but an injen. So the hose you spray the cleaner in for the IACV...would that be the hose that runs off the bottom plastic T that the valve cover breather hose and the hose running to the intake go to? I see it leads all the way to something under the intake manifold, so I'm assuming thats the one I need to spray...thanks

[zaquanh]

is this the same for a sr?

[I10cruiser]

originally posted by esone3
anyone know if this works for an sr?


yes, same hose on the cold pipe.
. . . .. . . . .

[zaquanh]

cool cool i used carb cleaner lol before , its all good ill be atcuallty taking it off soon anyways

[JRas]

I hate to bring this thread from dead, but also hate to make a new one and then get told to search when I already read this thread...but like said the pix aren't working. I no longer have stock intake, but an injen. So the hose you spray the cleaner in for the IACV...would that be the hose that runs off the bottom plastic T that the valve cover breather hose and the hose running to the intake go to? I see it leads all the way to something under the intake manifold, so I'm assuming thats the one I need to spray...thanks

post up a picture of your setup and we'll be able to help.

[Om1kron]

yeah I personally took my iacv/acc valve off of my intake manifold and sprayed electronics cleaner in there instead of "automotive cleaners." it blew all of the dirt off of the contacts and everything in there and I purchased a new gasket for mine as well. I just need to test it out now to see how that worked.

[s13pignose]

http://farm1.static.flickr.com/93/253799488_bbe82f6169.jpg?v=0

No pix under the hood of my car, so I found a s14 on yahoo
You see the hoses near the intake manifold... there's 3 that are all connected by a plastic t...one short one u see running off the intake pipe and then one long hose going the the valve cover. The one I sprayed in is the third that is on the bottom part of the t, and runs to some metal pipe underneath the intake manifold.

I used throttlebody and intake cleaner...sprayed and kept the motor from dying by reving the car by hand. I used only half the can cause parents were complaining about the noise lol, but that much seems to have helped. Earlier today my car seemed like it wanted to die at the light and while driving..needle on tach would sorta jump and drop a line. I experienced none of that tonight while driving since I sprayed the cleaner.

So I'm assuming I used the right hose lol..def was a vac hose

[s13pignose]

Forgot about posting in this thread..did I spray the right hose as I stated above?

Thanks. Also would AICV only affect idle/stand still or can it affect driving as well? I know the word idle is part of its name, but just wondering

Thanks

[Blitz671]

I apologize for bringing up this old thread but I just want to clarify which hose should I spray the intake cleaner into? Can anyone post a pic since the original pictures aren't working? Thanks!

[zerodameaon]

Scroll up to post 66. Cant miss the red circle labeled "HOSE", or I guess you can.

[ze12o]

It's the bigger of the two hoses. The one closer to the driver side.

[Blitz671]

It's the bigger of the two hoses. The one closer to the driver side.

Thanks! I sprayed it with intake cleaner and it definitely helped my idle issues go away.

[NJ240Drift]

picked up some B-12 chemtool carb, choke & throttle body clean. would this be good to spray in the hose to fix my idle problem ??

[soryu]

What about spraying some starting fluid?

[240sx44]

I can't see the pic you are referring too about which hose to spray the throttle cleaner in

[Rob's S14]

way to fail for your first post

[SoundEfx]

Why is it a fail when the pictures are not working?

[DriftEmperor88]

So I'm trying to clean mine but don't know which hose is it as well.... the pictures are not functional for some reason. Can someone update the pictures as to which hose it is? TYVM