Idle jumping from 2000-1500 Rpm After IACV, TB, EGR clean up
 

Hi I have Nissan maxima 99 ( 4th gen) with 168000 miles, After getting code for EGR tube, I followed direction from how to clean IACV from sticky. I have done everything was preety dirty i cleaned and put everything back but i saw one hose not to know where to connect I have attched picture.

https://lh3.googleusercontent.com/-M...September62012

now when i start car its on high idle around 2500 now after running 5 min it comes to 2000 rpm also it does weared thing rpm keeps jumping from 2000-1500 rpm also i did test drive and rpm doesnt go more than 3000 while i am drining.
The only problem i had before cleaning is code for EGR tube and when i drive car when engine is cold it was tring to stall but after that everything is normal. now i got all this problem
I also post video on youtube so you guys will know what am i talking abbout jumping rpm.Thank You

Sounds to me like you have a vacuum leak. You need to figure out where that loose hose goes.

That hose goes no where. Its a breather hose to, I believe the tranny. To pinpoint a vacuum leak, spray carburator cleaner over all hoses. If there's a leak you should hear a drastic change in idle.

I have the same problem. Tough to diagnose, just have to keep on trying things. Vacuum leaks are hard to find as a minuscule cut in a hose can cause a leak. Check them all throughly

what is Tranny.
i didn't chage EGR tube gasket coz local autozone didn't had any.

Transmission. That hose is the breather. I stays unconnected so tranny can breath.

So i should check all the hoses to make sure no leak is anything come to check leak like i saw in Autozone UV light to detect leak. also when i chage from reverse to drive car stalls or RPM goes low and kick right back when engine is cold any help appropriate.

Did you solve the problem and how?

Did you clean all mating surfaces and replace all gaskets, when you put everything back together? I cleaned my IACV, TB, and EGR guide tube this weekend and it's all back to normal. Before putting things back together, I smoothed out all surfaces with a putty knife, a flat head screwdriver, light buffing with sand paper, and my thumbnails, if there was any residue left on there. The idle was a bit higher after putting it all back together, but it was steady. I adjusted the idle down, with the screw on the top of the IACV.

I did not chage gasket for EGR tube as local Autozone didn't had. is this will make any difference.

how many hose each unit have IACV, MAF unit and TB

I'm no expert, by any means, but I've read others' comments on here that you should always replace the gaskets when removing and reinstalling most if not all parts. I know in my case, that part of the lower EGR guide tube gasket was ripped and stuck on there, when I removed it. It was only when I was using the putty knife that I realized that the main gasket was still on the engine, and what came off initially was just the top paper part of the gasket. The main gasket came off after I pryed it with the putty knife.

I knew it would not be easy to take all these parts off and clean them so before I started, I made sure I had all gaskets and even replacement screws, washers, nuts, etc, for the EGR guide tube. I did not want to take any chances.

Hi i clean like this also want to know can i open IACV from otherside by removing 2 screws
http://i150.photobucket.com/albums/s...3/P6090015.jpg
http://i150.photobucket.com/albums/s...3/P6090020.jpg

Gee, I'm sure you could probably figure out the majority of your problems if you figure out why the check engine light is on.. just saying.

I took apart the other side as well, but be careful with the part that is connected to the brown clip. I didn't get that wet at all, and it is loosely together, meaning if you turn it the wrong way, the spring will fall out and you better know how it goes back together. For the other side of the brown part, with the pointy top shaped like a cone, I only used a brush/cloth on it, and did not spray it directly. My wife actually had a baby bottle cleaner that I was able to use (tiny little brush), and I poked it into every crevice I could on the IACV, and the other parts I cleaned.

There is even a tiny opening on the IACV where the idle adjustment screw is, where I cleaned a little crud off with the brush, and then sprayed/wiped it clean.

Have you checked the hoses for leaks? Maybe you bent one and it cracked, or maybe you left one disconnected? How about the tiny one that takes air from the airbox? For that one, I only disconnected the side on the airbox, so I don't even know what the other side is connected to.

Yes i opened other side thinking i need t clean that also. and yes the small spring fell also i cleaned whole thing with spray, (throttle body cleaner), anyone has picture to verify on fitting i dont know how exactly the spring fit i just insert the spring. may be i messed up that part.
also someone told me it could be fuel pump he want me to do fuel pump pressure test or may be catalytic converter pressure test anybody confirm that but i am doubt car wasn't doing this before i open TB, IACV, and EGR tube.

The part with the spring that fell out is a motor that pushes the other side in, letting more or less air pass, and by getting it all wet with spray, you may have screwed up that motor. I remember others posting on here that you have to be careful what you spray inside the IACV. You may want to try getting a replacement from a JY. Since I'm not an expert by any means, you may want to wait to hear others chime in, before taking your next steps...

the spring was separate it wasn't connect to any other part when it fell.

any help, Please

I wasn't just being a smart ***. I was being serious.

ok i got code for KS, IACV, and MAF just want to know while car was running i unpluged MAF sensor to check that time their was no code when i unplued MAF sensor wire engine stall and now i got this code just want to verify

Go to your local auto parts store and get some CRC "mass air flow sensor cleaner" and clean the filament inside the maf sensor. Just spray it on. Do not touch it with anything else.

Check your wires for the iacv and make sure they're all plugged in

Yes i cleaned same way. But i want to know if i unplug MAF sensor plug while car is running will car stall and i get the MAF sensor code. my car is stalling may be that reason i am getting MAF code. about IACV i orderd another one coz i opened it and spayed the spring part and i thing i fried IACV

Fixed the problem now idle is smooth and around 650-700 . The problem was TPS adjustment. it was way out of range now i set it up to 500@ throttle closed and when i WOT is @ 4007
Thanks guys for your help

Nice work getting it running properly again!

Why did you remove the YouTube Video?

For like the 285762848473628484728th time, that hose does not connect to anything. It's a breather hose for the transmission.

the UV light is to detect the dye in R134a refrigerant, to see where your A/C is leaking, that is all.

wat

cant go pass 1200 or 1500 rpm
 

can anyone give me an idea whats going on with my 95 maxima. My rpm seem to dont go past 1500 rpm while im driving when i rev its smooth but at idle its around 500 t0 600 rpm when i go into the gears first gear the rpm stays at 1000 or lower rpm but the engine roars fine when the car is warm its at descent rpm 1000 or under at idle but while you driving it doesnt move much the rpms rather what can be the problem i thought it was the MaF i replaced that the IACV is new from autozone adjusted the idle on the throttle body small screw on the throttle body nothing same issue:(