air filter is new
im also having a feeling that it could be MAF or after i saw my relatively new spark plugs looking like sh*t something to do with ignition
and today when mechanic told me his 99% sure opinion that its tranny..im all confused

 

Sounds like the torque converter to me!

 

how do i chek it and where is located?
thanks

 

bp doesnt have their own gas anymore, its amoco supplied, and amoco is some of the best gas you can get, anyway
could it be your TC slightly engaged even more than usual? cus its like stopping with no clutch, the engine is still engaged and its killing it, thats just my guess

 

if anyone can confirm it is the TC, it'd be much appreciated..

 

ITS THE IGNITION COIL! i just changed mine today. that stopped the thrusts . and the vibration was my knock sensor. i changed both without heavy labor. WHOOOOOO! nice.. my 6th ignition coil was hmm ? broken like it broke into two pieces.

 

I have a palm dyno-scan and i never got a code nor a pending code for mine and it is not the tq. im guessing a dirty fuel injector? When coils are going out you get a code.

 

Fuel injectors would be the one thing I have done too much with yet. Where can I get some good info on this testing procedure? Or maybe first a really good cleaner?

 

FYI:

Here's a valuable web site about idle problems:

http://www.2carpros.com/topics/idle1.htm

 

i had the same problem last summer when i first got my max.... they said it was the sensors...

they didnt go into complete detail but they just said it was the sensors and my **** was fixed

 

ok here we go, just came back from the Nissan dealer i was sitting there from 7am until 4pm how about that?
the problem was : Main engine wire harness from firewall area to & around shock tower. There were 3 cut wires.
and Im sure nobody wants to hear how much it costed to replace 3 damn wires....$435 but 2 other regular auto shops could not detect the problem so i had no choice.

 

the problem with mine was i asked my mechanic. it was my 5th ignition coil which i bought for $62 and then i changed my knock sensor . and the problem went away... everyone check your ignition coil.. it comes out when u get the palm computer. thats theres a misfire. MY CAR RUNS GREAT AGAIN. except when i hit 2nd gear my handle shakes a lot. maybe axle shaft defect but as soon as i kick into 3rd and 4th
im gOODDDDDDD

 

Did you have any codes or a check engine light? which wires got cut? (to which sensor)

 

nope chek engine light never came on, i went to 2 regular auto shops they did diagnostics it didnt give any codes they had no idea what the problem was, one even suggested that its the tranny. Once i came to the Nissan it took them about 5min to find the problem, i guess they got different type of computers there. I cant belive the car finally runs great and feels like a Maxima again. The sad part is that they charged me a sh*t load and i spent 8 hours in the waiting room.

 

What wires were cut?? And what were your cars symptoms?

 

Oh yeah and how did you cut the wires?

 

in the bill it says "repaired Air Wires" but i dont know how accurate that is. There were 3 of them cut off and few around them looked bad, so there was a section of wires replaced about a dozen of them.

The symptoms i mentioned in the thread above...it first started by car shutting off very often when i tryed to back up by putting it to Reverse or Drive but not as often and lately it just started shutting off whenever it felt like, on the trafic lights, while driving especially when making turns. Sometime it would shut off right away, sometime the rpm would jump up and down then fall as low as .3 and then stoll out. Or sometime it would just drive perefectly like nothing is wrong

I thought it was the MAF or Ignition coil, in one of the shop they suggested it was the tranny but i would never even have a thought that it could be the main engine wiring harness

 

no idea man, my guess would be they werent cut but rather melted due to some electrical shortage..?

 

hmm.. it might not be the wire for me because my car doesnt completely shut off.. it just vibrates violently at stops.. but never shuts off. im gonna check the ignition coils and fuel injectors the next chance i get..

 

i know someone who had similar problem as yours with a Sentra and the problem was the ignition coils...so yea i guess chek that first

 

But if your not getting a code or a check engine light it is not the coils. It is something flying under the radar. Mine doesn't shake violently but it is more shaky than normal. Not bad but not normal, it started a couple weeks ago. I quess a normal person probably would not notice it but i notice everything. And i have a palm dyno-scan and i can watch my idle dance between 615-680 underload. And it does it in nuetral to so its nothing with the transmission??

 

same problem here at stop with trans in D car shakes a bit more than normal but RPM dial stays still near 600. Shaking is harder when AC is on.

All services are done recently including cleaning coil packs, IACV, EGR, TB ,...


Your information to find the cause of this will be appreciated.

 

same problem here....

From reading this thread I think it's either an injector or torque converter....will check out this weekend.

BTW: I've got 61K miles and a brand new tranny.


- Jay

 

Tough to find so many things can cause this...but if the engine runs well at advanced RPM my bet would be air intake to the engine. With the engine idling, the only air entering the engine should be through the Auxiliary Air Control Valve (AACV) and it's two little sisters the FICD ( I have no idea what that stands for!) valves. All three valves are mounted on a manifold and together form the Idle Air Control Valve (IACV) assembly. Basically, the IACV does this:
1.Adds more air through the FICD valves (solenoid type needle valves) when the A/C is turned on and/or the Power steering pressure is elevated. The reason for both of these actions is to preclude an excessive drop in RPM when the engine is at low RPM and the load on the engine is increasedby the PS and A/C.
2. Next, and more critical is the function of the middle valve the AAC valve. This is a motor operated valve and maintains the engine speed with the help of the Crankshaft Position Sensor (POS) based upon pre porgrammed values in the ECM. The ECM monitors various engine parameters to come up with the engine speed to achieve.

Now, the fist thing I would do is check the AAC valve. Do this by removing it from the body of the IACV (my 97 has two Phillips screws and an O ring under the flange). I bet it is really dirty - use Thrttle body cleaner to clean it up. Do not turn it! it does not work that way. After you clean it check it out and reconnect the harness connector, put it so you can see it through the windshield and just turn the ignition to on (don't start). You should see the end of the valve (plunger) move smoothly in and out as you switch from on to off ignition. If not the valve or wiring is at fault and that should be your problem.

Remember we said the air to the engine is controlled only by these valves...what else could bypass air (or gas) into the engine? basically two things: a manifold vacuum leak or a stuck EGR valve.

without too much description, the purpose of the EGR - Exhaust Gas Recirculation valve is to do just that to cut down emmissions. Old Idea used on most if not all cars. But if this valve is hung up, dirty, or the vacuum solenoid valve to it not working, the bad gasses rob the engine of air to breath and you wind up with a rough idle. Many ways to check it out, but you need to make sure the valve is functioning - you'll probably get a code during the process.

Mike

dle Air Control Valve ,

 

I bet by now everyone has figured it out that codes don't tell you the problem, they are not intelligent. Codes are only the result of ECMmonitored parameters out of specification and as such only tell you symptoms not diseases.

Why don't we write a program to intelligently analyze codes on the fly...based upon occurrence, timing, frequency....

 

I am quite surprised that we've gone through the whole nine with this shaking problem and nobody has actually considered that their engine mounts may be bad. Shaking while idling is a symptom of bad engine mounts people. Just wanted to put my 2 cents in...

 

f**kkkkk. After $435 and 8 hours at the dealer, car ran amazing all day so perfect that 125k felt no more then 25k, but as i was coming back from work all of a sudden it shutted off at the light and then on the bridge again(almost freakin killed my self) cant express how pissed off i am just simply can not believe that sh*t. Going back to Nissan as soon as they open at 6:30 im in the mood of killing them all head by head.

 

Virtually all of the suggested causes and remedies posted here are valid.

As proof of such, if you happened to click on the link I provided a couple of threads up, you would have realized just how many different causes there can be for rough idling and shaking.

It is analogous to the human headache. Is it due to an allergy? Is it due to a cold or virus? Is it due to being hit on the head? Is it due to having too many beers the night before? Is it an eye-strain due to reading too much Maxima.org?

You get the idea.

Unfortunately, we don't have Advil for Maximas, so we need to use a process of elimination.

My diagnosis & repair strategy is a variation of Occam's Razor: to start with the simplest (or sometimes the cheapest) solution that I, personally, can do, and proceed from there. That is the reason why I tend to check things like loose connections in electrical circuits or leaks in vacuum lines (after first checking for error codes on my OBD-II scanner).

What's amazing is how the least expected cause turns out to be the culprit. For example, I had rough idling, too, about a month ago. I traced it to my stock air box on which the snorkel outlet had disconnected itself from the air box and allowed nice, hot air to pour into the opening. Once I reattached the snorkel, the rough idling stopped.

I also learned that, on my car, the resonator elbow helps to keep the snorkel attached to the air box, and without it, the snorkel had pulled away.

On my previous car (a 1992 Max), the car would idle just fine on cool days. On very hot days, if it sat idling for more than two minutes -- for example, when sitting at a long, stop light, it would start to idle roughly. Putting it into neutral had little effect, but putting it into drive and moving forward a few feet made it stop!

After months of testing, I never did find the cause of the problem, but my solution was to change my way home from work, and thus avoid having to sit at the long light. :-)

 

What the hell are you talking about? Bad motor mounts? Yeah they cause your idle to fluxuate. Please follow along with all out posts or don't reply. And the dealership sure screwed ya man i'd be pissed. It was probably just an excuse because they had you car all day and couldn't find out the problem. I thought everything was by the book labor wise? You look in the book and it tells how many hours labor and they bill ya. How could they charge you that much just for trouble shooting? I had bad wiring on a 95' pathfinder, it would not start all the time and a shop had it for 2 days and only charged me $70.00 for labor and 2.00 for the wire and said that they could not charge me for all the hours of labor it took them to find it. But i guess they all are different.

 

Here's another option, a buddy of mine with a 300zx TT said he was having a similar problem (5-speed though), turned out to be the AAC valve, part of the iacv unit. I'm not too familiar with this but from what I've dug up, if you disassemble the IACV further you can clean/lubricate this part. It is a spring loaded valve, but if it gets gunked up it may not close all the way at idle and simulate a vacuum leak. This is definately worth looking in to! Another idea he mentioned was coolant temp sensor as the problem gets worse for some of us as when the max gets warm.

 

already done that, and mine is the same hot or cold. I think this is kind of bs considering my car only has 51,000 miles. Man does it need pampering.

 

ok 2nd trip to Nissan dealer.
turns out that the cut off wires in the main engine harness was only half of the problem, the other half turned out to be the MAF sensor(meter) which according to the mechanics was damaged due to the shortage in those cut off wires, how did they get cut off under such taping is beyond me unless the MAF was broken first and caused those wires to melt, so anyways new MAF from Nissan costed me another $480 so all together with sales tax i ended up being screwed for $990.
Although i got my alternator and power steering hose clamp replaced for free as they are being recalled on our model.

 

After 3 days of leaning over my engine I finally got her all back together

I've been having the same trouble a couple months now, checked the ECU came up with EVAP purge valve many times and have yet to replace it, recently I got, cylinder 5 misfire and right bank 02 sensor. Well at one point it was only the EVAP but then the car started running really bad so I had to do something.

Well I tested the rear injectors (cylinder 5 mainly) using the method on VBXmaxima or whatever, it tested bad so I had to replace it. After removing everything (TB, IM, IACV) I found that sure enough injector #5, there are these little plastic claw looking things on the end of the injector well a couple of the claws had broken off, and the injector itself was a little worn and crooked.

I destroyed another injector trying to pull it out so I figured if I'm buying two I might as well by one more and do the whole rear bank so I wouldn't have to do this again.

I cleaned the hell out of the IM, IACV, TB, all of which were coated in thick black crap(140000miles) I looked into the lower intake and could see the valves, well in cylinder 5 there seemed to be a pool of gas. I used a turkey baster with a hose taped on the end and sucked that **** out, then I sprayed some intake/TB cleaner in there and took off a lot of gunk, then I sucked that **** out too and there were chunks in it!
I saved it in a bottle I'll take some pics and show them. I took a bunch of pics but I left my camera in my buddys max.

I got it all back together today, it started really rough, then I reved it a couple times and big white clouds of smoke came out of the exhuast, so I was looking at the engine will it was running and noticed there was fluid spewing out of the connection between the y-pipe and the front exhaust, turns out it was gas. Well I couldn't figure out why there would be gas leaking into the exhaust like that. So I thought maybe it was just excess fuel not being burned, that would also explain the thick white smoke. So I let it run under a close eye and a fire extinguisher by my side. It stopped spewing gas and the idle started smoothing out.

NO MORE SHAKING OR JERKING AT LIGHTS!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !

I still have to replace my EVAP purge control valve, I still have a little stutter when I come to a stop (deceleration) and I believe that is associated with it. But at a stop and any time the throttle is open there are no problems.

Anyway my solution was a new injector, although it took a while for the ECU to ever detect a fault, like I said I have had this for a couple months now.

Wow i talk to much.

 

^ wow congrats.. i still havent had time to check my injectors, hopefully my experience will turn out to be the same as yours.

 

I have the same problem. When im stopped the car shakes but very lightly. My father is a machanic, hes been driving it for a day to see if he can figure out what it could be. So far he says it sounds like something about i vacum, i didnt understand him completely. He says he will try to see if he can figure it out him self, otherwise "You should take it to the shop". He would fix it him self but hes an old man and too tired to fix it.

 

Mine isn't running rough but I have always wanted to take the IM off to clean it out really good. To me,it seems my car would run smoother/better if the IM was cleaned out b/c if a dirty throttle body can affect your engine I would imagine that the IM is filthy and a good cleaning would do alot of good.
I also thought that if I got the IM off I would see other gunk that could be cleaned and you pretty much confirmed what I was thinking.
To me it doesn't seem like it would be that hard to do(take the IM off).
How long did this process take. Will I need another gasket for the IM when I take it off? I would appreciate the help. Thanks.

 

I think I may have jumped the gun. I reported that the shaking and jumping of the rpms was solved by a new injector, well today at a stop light it did it again, just once or twice but I was pisted. It didn't do it again but still, I am still getting a code that reads EVAP purge control valve/selenoid valve, I still haven't replaced this as it is $114 and I spent most of my money on the previous repair. I am going to attribute the jerking and **** to that. I will know next FRI when I can buy one and replace it.


I was driving around today and my cel came on so I checked it, front 02sensor, EVAP..., and cylinder 2 misfire. Well I'm pretty sure it is not the injector as I just removed it cleaned it and put new o-rings on it. I know its not the spark plug because they are relatively new and I checked it and it was fine. So that leaves the coil. I moved the #2 coil to the #6 cylinder so we will see if it misses on #2 or #6

The cel came on again after I did that but only showed the front 02 sensor, I'll have to wait and see if it shows a misfire, as for as the 02 sensor and the EVAP purge valve, I can't do anything about those until next THU.

HUNTER11 that is a sick looking max!! Mine is pearl also But I need clear corners and a spoiler. And some tight rims like yours.
Anyway, removing the IM was really not to difficult,(except a few bolts) It took me a few days because I had to work from 3pm to 11pm so I didn't have much time during the day. There was one day I had off I worked on the max from 10am to 5am the next day And it didn't help that I had to drive 1 hour away from my house to go get a $4 ****ing TB gasket.

But really just:
-Remove air intake, I removed most of this in 2 large pieces
-Remove Throttle cables, two screws hold the bracket they are in, and unhook the cables(check your manual)
-Remove the Wiring Harness, there are a few metal brackets that hold the WH to the IM I think 7 or 8 screws, remove those, unplug all connectors and your good there.
-Remove the TB, disconnect hoses, throttle position sensor plug, vaccum
lines.
-Remove IACV, diconnect plugs, any vaccum lines, un-bolt.
-Remove all bolts connected to the IM, you have to do the front four in the reverse order of tightening(check the manual) then the two in back that attach to the rear of the IM then the two that attach the EGR valve guide tube, to the back of the IM near the IACV. Also brake booster hose and any others,(there are others) that you see.


Then you should be able to lift the IM off. You may need a new plenum gasket(IM). If you are removing the valve covers you will need new gaskets for them.
I got a gasket kit from AutoZone which had the Valve Cover gaskets, spark plug tube seals, new grommets for the valve cover, I did have to buy TB gasket, the IACV gasket was good, and so was the plenum gasket.

There is lots of **** to clean out of all those parts!! In hind sight I should have removed some of the hoses that connected to these parts and cleaned them out too. If you want to check your Injectors while you have the IM off you will need new o-rings. I destroyed one injector pulling it out and I found another that was all cracked and ready to die. SO I put all new ones in the rear so I wouldn't need to remove everything again.(hopefully)

All this is in the HAYNES manual, if you don't have one get one, and some more specific info(like about injectors) I got right here at the ORG.

If you have a couple of days to COMMIT to this and you get all of your supplies FIRST(gaskets, screws, cleaner, cleaner, cleaner, and anything else you may want or need.) it can probably be done in two days.

 

^ ah damit, so it wasn't the injectors? .. well im glad i didnt go ahead and buy new ones just yet.

 

My 98 max was doing the same thing but it turned out to be a missing spark plug boot from when i had installed new NGK's, apparently it will arc inside the engine and cause a misfire, but it never threw any codes.

 

I've been having this problem for a year and a half. My engine throws no codes. I've gone through spark plugs, coil packs, TB cleaning, PCV valve replacement. Whenever I take my car in somewhere for the periodic checkups, I tell them the engine idles roughly and they say they've fixed it (various simple reasons like plugs or PCV valve), but they never do.

I've brought this up on the board before, but I never got responses like this.

Something to consider, also, is that I don't feel my A/C is kicking in very hard. If you go to auto.yahoo.com and look up our 4th gen maximas, they mention a "wiring harness" on the right side of the car as having reliability problems - the wires fray and cause rough idle and weak A/C performance. Again, no mechanic I go to has ever mentioned this to me, and I don't even know what the hell they mean by "right side" of the car.

I have little to do this summer except fart around on my car. I'll check every potential problem on this thread and the afore-posted rough-idle-faq if I have, too. Oh, and I'm going to sneakily replace one of my roommate's reverse lights with one of those bulbs that also beeps.