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 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.


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:

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]

Originally Posted by JigokuZ

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]

Originally Posted by nsn240

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]

Originally Posted by DRFT

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]

Originally Posted by Milky6

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

+1
_____________________________________________

[TipStylez]

Thanks alot for posting this!...

[aznpoopy]

Originally Posted by pf doom

+1

get an fsm...

[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]

Originally Posted by mrmephistopheles

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]

Originally Posted by 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.

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.

[sittinsideways]

Originally Posted by 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.

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]

Originally Posted by DrifteRs13

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]

Originally Posted by 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.

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?