Car wants to stall out... Possible problems?

[S13ChucKAT]

Well.. i just got my S13 yesterday, KA24E powered.

While im driving my car, and go into neutral, the rpms drop down to about 10...20.. 50-200. then they go up twards 1000-1200 when i give it some gas..

Ive narrowed it down to what i think a few possibilitys are.

Vaccum hosesMAF (but i can still rev up past 3-4k)Spark plugs/Dist cap/rotor/Fuel pump?

If anyone else has fixed this problem, let me know.. I have a 200sx as well.. been screwing around with it for 2 years. so im pretty familiar with nissan.. but.. hmm

[navysnail]

pull your spark plugs and check them, see what they look like.clean the maf out with brake cleaner, dont spray teh hot wire directly though, its sensitive.vaccum leak is deminately a possibility, listen for rushing air or spray them with carb cleaner and see if engine speed increases. the aiv may also be putting exhaust into the intake, check that out if you havent already.

[S13ChucKAT]

Yeah, this car is in major need of a tune up (it was sitting for like a year in a trailor park.. and had bad gas.. but i drained it, and filled it with 93, and its running like a pro, minus motor mounts, and the low idling issue) ill be checking it out later todya

[Dattebayo]

Replace your oxygen sensor. Your ecu is running in safe-mode.

You dont need to clean the MAFS, it irrelevant for this. If you must try it, please use a less caustic type of cleaner.

Try cleaning your throttle body with some throttle body cleaner from your parts store and a plastic big pipe cleaner looking brush.

Also, adjust the idle screw on the back left of your engine and see if the engine idle changes smoothly or suddenly or not at all. If suddenly or not at all, you must replace the IACV. (intake air control valve) This valve controls the cars idle directly so its important.

[S13ChucKAT]

im about to do a decent tune up today. so.. ill stay tuned with how it goes.

[NisMoSilEiGhTy]

i had this problem when i put my intake on the car b/c of a vacuum leak....also i would def try the idle sdjustment screw and also if the car is old u could have lots of carbon build up rev the car really high while its in neutral and see if a lil bit of black smoke comes out...i had alil bit of rough idle even after i fixed the vacuum leak and i seafomed out the car and it runs like it just came off the show room floor

[S13ChucKAT]

seafoamed?

[S13ChucKAT]

Holy mother of gosh!.. I started doing my tune up.. and after fixing a few hinges/struts/ seals/ mirror.. i went to the engine..

Engine mounts are GONE.. just loosening the sparkplugs, my motor rocked.. but check this out.. heres the funny thing

< PLugs im putting in

< plugs i just took out. these are gapped PAST 1.0MM.. i thnk i found my cantadate to why my idle is bad.. soon replacing fuel filter/PCV valve / dist. rotor/cap

[S13ChucKAT]

Ok.. replaced everything ecept O2 sensor.. Im saving that for tomorrow. im totally stoked.. just got out of the shower.. covered in grease/gas/oil/radiator/brake/PS fluids.. lots of cuts from jagged.. stuff in the engine bay.. Oh yeah, feelin good.. tomorrow the O2 sensor is going to be replaced.. so far idle seems steady at 650 now..

[Dattebayo]

If it doesn't raise the idle above that, you should re-adjust it up to 700 rpm.

[S13ChucKAT]

welp, after trying all that tune up Minus O2.. after actually driving it alot.. its more powerfull. but the idle is still h0m0.. and i looked for vaccum hoses.. all were in tact, and no squishy ones... im still going to replace that O2 though, like you said, Gay-mode

[Tsukai240]

what about the TPS could that be it. i'm having the same prob.

[Dattebayo]

It could be the TPS, but you would have problems in other ares than just at idle. For one thiong, your mileage would be all frelled up; you would notice better gas mileage at weird intervals. Try wiggling the wires that lead into your TPS box at the side of your throttle body or tapping it lightly.

[S13ChucKAT]

update.. after a FULL tune up.. O2/pcv/spark plugs/cap-rotor/oil change.. it does the same ****... to make it more... point out able.. upon pushing the clutch in, it will go to almost dead.. like.. if i hold it in while driving, the car will actually sometimes throw the brake/alternator light on likes its off.. but then slowly idle back up.. but then if i sit there, and let it climb up, the idle goes to about 1100 and maintains..

[ziggy682]

This is a very common problem that most of us have, yet noone seems to ever know how to fix it.

Everyone will tell you a different solution that they've heard might fix it, but noone ever really knows.

Well, my car used to do it, but it doesn't now.

After trying everything under the sun. Removed and cleaned the IACV, removed the AIV, checked and cleaned the MAF, checked the TPS, changed plugs, O2 sensor, etc. The solution came by accident whenever I turbocharged my car. I removed the EGR system because I didn't want to put an EGR bung in my downpipe, and the idle problem went away. The EGR recirculates exhaust gas into the intake manifold to help warm things up faster, and reduce emmissions. My theory, is that the diaphragm that controls the EGR gets kind of sticky after a while. When you let off the gas, it lets too much exhaust back into the manifold and kind of chokes the engine out. One of the tests to see if your EGR is working is to reach up under the diaphragm, and push it up...if your engine bogs down, then the EGR system is working. I think, as our cars get older, the diaphragm just doesn't work quite right anymore, and results in the bog at idle. I removed my entire system, and made a block off plate for the intake manifold, and my car idles great now. I used to blip the throttle every time i put the clutch in to keep the car from bogging, but those days are over now.

Like I said, this is just my theory, and I haven't varified it on any other cars.

Hope this info helps.

[S13ChucKAT]

hmmm i might have to check that out...

[ScottnAshley]

i had teh same problem when i pushed in my clutch it would wanna stall out i did everythign you did and i was stumped and guess what it was.....?!?!?! THE AIV take the whole damn thing out cap off the hoses and my car idles perfect. just try this even if it dosnt help you dont need teh AIV anyways. It only takes like 30 minutes to take outand cap off. no loss but maybe may fix all your problems!

[S13ChucKAT]

didnt effect your gas mileage?.. anything of the sort?..

[ScottnAshley]

no it didnt i get the same as before. what i did was take teh 3 bolts off the braket holding it then it comes right out. after you have it out it has 4 hoses one to the air box filter, one to the exuast, and to runnign to teh intake. the 3 bolts you took off to get the braket out plugs the 2 small hoses. then find a big bolt or somethign like that and plug the big hose going to the exuast or order the plug from nissan dealer. then plug your air box with a bolt. there is one electricle connection to the AIV just unconnect it and leave it hanging. U get no codes and i never had an problem with it out. Like i said and others said the newer models didnt come with one. Its very simple and if you want a better write up type it in SEARCH "AIV REMOVAL". After doing this to my car if never dropped in rpms nor stalled ever again. Its kinda funny how one thing can cause so many problems. But this could not be your problem but its worth a try. If its not and you want it back it just unplugg holes and drop it back in. Good Luck.

[S13ChucKAT]

Yeah, ill be checking it out, maybe when it gets a lil cooler out, like night time in my garage, houston owns me

[ScottnAshley]

did it work out ?

[Julio Bro!]

Hi, I'm having the same problem this days after an overheat problem and problably will try removing the AIV and replace the EGR. Some questions though:

* What is the function of the AIV and why it's not needed? Where is it located?

* Is the EGR diaphragm, or the part that contains it, replaceable? There is the EGR-BPT valve and the ECM controlled EGR valve, which is the one to eliminate and why it's not needed?

* EGR seems to be related to emmisions, will any of this impact emmisions testing?

I'm reading the ECM uses coolant temperature in relation to these systems, could a code bring up the idle problem?

[ScottnAshley]

The AIV was designed to heat up the cat faster. Im guess the car dosnt heat up as fast as the engine? Well, Look at the box on your intake and follow the one hose comming outta it youll see a black box. Thats the AIV.

From what ive heard you can complately take out the EGR valve. But i dont recommendit if you have emitions. You will fail the test! I believe its all replaceable.

Yes, No EGR will make you fail part or parts of your emmisions.

When my idle was going crazy i got no code. So, except the AIV dosnt mess with emmisions nor does much to the car at all. I took the damn thing out and my idel went strait to normal. If you dont want to take the AIV out for good just try cleaning it and put it back in. Remember and try and start the car while its out and see if it fixes the idel all the way.

[driftin8ez]

Ok my car idled like crap when i got it to. This what i did.1) Had the aiv cleaned but later just yanked it out.2) I also replaced a vacuum line that goes to the egr. The egr vacuum line that was cracked made me fail emisions and also gave me a crappy idle. here is a post on how to fix it. Just read down i think nistech made the post. http://www.nissaninfiniticlub....sions

so the aiv has nothing to do with emisions but the egr will fail you if it is removed or working incorrectly. Try and see if the vacuum line has a hole like mine did. I attached a picture somewhere in that post.

3) I also seafoamed my entire engine all 3 ways. after i replaced plugs and o2 sensor.(becouse they will get fouled after the seafoaming. Car idles like a champ and also runs stronger than a friends 240:-)

How many miles does your car have?

[S13ChucKAT]

im at 130k, but considering doing a head (dohc) swap. luckily i have a ford ranger that i can drive while the 240 is down.. I just need to get a parts list on what car i need what from.

I have decided not to care.. im going to save until i have enough for the head swap.. then im going to get rid of everything vaccum related except the FPR, EGR, Brake booster.. and thats it.. everything else that i can get away with removing, will be done so

[Julio Bro!]

I have a 1993 240SX SE with 137K in the odometer. It's well maintained; I pour a fuel system cleaner at each oil change, only synthetic oil, Bosch+4 plugs and Stillen K&N intake (recently changed).

You know, when I changed the filter I got that idle thing for 2 or 3 days then gone. Now I got it when overheating and after flushing and replacing thermo and fan-clutch. I thought the computer takes some days to adjust when repairing or improving things, this because when I originally replaced the intake (year 6 on the car) idle got affected for 3 days and then gone; also when replaced exhaust tubing for 2.5" system.

The AIV takes fresh air how would that help in heating? I read at ALLDATA that the system helps in reducing CO and HC, and the EGR helps in reducing NOx. So both intervene in emissions, although it seems the AIV is not that efective.

I would like to know if someone got bad emissions after removing the AIV? Any web store that sells this parts?

[Julio Bro!]

so the aiv has nothing to do with emisions but the egr will fail you if it is removed or working incorrectly.

So you passed emissions with the AIV removed?

[ScottnAshley]

No emissions in flordia. But i heard so many people say it im startign to believe it dosnt. Ive heard no one say the AIV caused them to fail from 95+ 240s didnt come with a AIV because it caused to many problems

[driftin8ez]

yes i passed emisions with the aiv. And i'm in NJ the second hardest emisions test to CA.

[Julio Bro!]

I live in Puerto Rico and I think our emissions parameters are the same as California....at least cars are California specs.

I've been reading here that almost everyone has removed that part from their system, I would like to know for sure that newer models came without AIV.

I also read that I can buy a "factory" plug for the AIV exhaust hole, have you bought this?