# 2007 Maxima Idle problem and running oddd



## RichieMax (Feb 22, 2016)

first had this issue about 8 months ago. My car would run fine in the morning and then in the afternoon or after sitting in it for a hour or 2 while in park I would shut it off and then 10-30 minutes later it would be a very long crank. then once it kicked over it would bog a little and i would hit the gas and then it would be fine. It didn't happen frequently and then it started happening often so the mechanic could not find the issue. Eventually it got so bad and then also the idling at lights and sitting in it at rest it finally almost stalled once and then when i started it it had a code P0300, random misfire code and 3 cylinder misfire and throttle position code. 

The mechanic gave a tune up, replaced throttle body, all sparks plugs and 1 ignition coil.
the stalling and all codes did not come back except but 0300 then p0174 and intermittent rough idle upon hot start up still present.
Fuel presssure was fine, raised idle to 200RPM's but still the issue.

Then they replaced the mass air flow sensor and bank 2 air fuel ratio sensor, problem still exists and the P0300 code still present.

Then Replaced all Fuel injectors and rail O-Rings as per recommendation of Nisssan Head Tech. Condition returned on second startup and P0300 present.

They sent it to a computer specialist, had it for 6 days and theyre is no code and he can not find a problem.

Mechanic told me if it persists go straight to Nissan for a ECM.

The car has no code at the moment but idle is running odd( if i tap the gas pedal it shoots up to 2-3 rpms real quick and at idle in park or at light it just doesnt feel right, it doesnt drop below 1 rpms much but feels like on odd run, almost like its iddling normal but putting at same time. Now also once in a while i get a long crank.

Any Suggestions would be great. I keep researching it and it all seems to come down to the IACV and ECM needs to be changed ? Any Idea because i know this is expensive and dont want to do anything for no reason. Car is almost like new after all this work andi prefer not to get rid of it. it only has 90,000 miles and had all this done and would prefer to keep it for a long time. 
Please anyone have any clue ???????


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## jdg (Aug 27, 2009)

I don't see anything in here about the coolant temp sensor.
...which may or may not be the difference between a mechanic and a technician...



RichieMax said:


> first had this issue about 8 months ago. My car would run fine in the morning and then in the afternoon or after sitting in it for a hour or 2 while in park I would shut it off and then 10-30 minutes later it would be a very long crank.


First thing in the morning, CTS is supposed to be bone cold. ECM compensates accordingly and gives it extra gas (eg. like a choke back in the day).
In the afternoon or after it's been parked, warmer outside, warmer under the hood. CTS is supposed to be reading warmer, but it's still reading cold. ECM kicks in extra gas...engine has to burn out that gas.



> then once it kicked over it would bog a little and i would hit the gas and then it would be fine.


...which is when the engine is burning out that extra gas.



> It didn't happen frequently and then it started happening often so the mechanic could not find the issue. Eventually it got so bad and then also the idling at lights and sitting in it at rest it finally almost stalled once and then when i started it it had a code P0300, random misfire code and 3 cylinder misfire and throttle position code.


And the mechanic goes straight for the codes, all the codes, and nothing but the codes.



> The mechanic gave a tune up, replaced throttle body, all sparks plugs and 1 ignition coil.
> the stalling and all codes did not come back except but 0300 then p0174 and intermittent rough idle upon hot start up still present.
> Fuel presssure was fine


Ok, maybe there was a few marginal parts in there that may or may not have contributed to the codes.



> , raised idle to 200RPM's but still the issue.


They raised the idle? An ECM programmed parameter...they raised the idle RPM? Now that's fishy...



> Then they replaced the mass air flow sensor and bank 2 air fuel ratio sensor, problem still exists and the P0300 code still present.


And again, straight for the codes...



> Then Replaced all Fuel injectors and rail O-Rings as per recommendation of Nisssan Head Tech. Condition returned on second startup and P0300 present.
> They sent it to a computer specialist, had it for 6 days and theyre is no code and he can not find a problem.


Nissan head tech and specialist don't look so special now.



> Mechanic told me if it persists go straight to Nissan for a ECM.
> 
> The car has no code at the moment but idle is running odd( if i tap the gas pedal it shoots up to 2-3 rpms real quick and at idle in park or at light it just doesnt feel right, it doesnt drop below 1 rpms much but feels like on odd run, almost like its iddling normal but putting at same time. Now also once in a while i get a long crank.


Another part I don't see here is the crank position sensor. An obvious one for any decent technician, whether a code is present or not.



> I keep researching it and it all seems to come down to the IACV and ECM needs to be changed ?


An IACV seems likely as well, but any decent mechanic that's been to any decent school for 15 minutes would be able to troubleshoot that out of the picture.

So, in short,

Coolant Temp Sensor for the rough hot starts...possible. Again, any decent tech should be able to troubleshoot that with a scanner, or heck, even an ohmmeter.
Crank Position Sensor...a bit tougher to troubleshoot but easy enough to change and figure out. A bad CPS doesn't always throw a code, but one of the codes it WILL throw would be for a random misfire.
IACV...again, for the rough starts and rotten idle. It's right there in the name...Idle Air Control Valve. If the ECM thinks it should be working, but it's not because it's all gunked up with carbon/crud/etc, the ECM doesn't know carbon from crud. It only knows that electrically, it's trying to adjust the idle rpm by using the IACV.

'nuff said.
It's not that I'm against dealerships, mechanics, etc. What I'm against is these 1 year school clowns that pass themselves off as fully trained mechanics, but they only know what's in the book (eg. can't solve a problem they didn't see on a test somewhere). Clowns that can't think outside the box and tie things together (eg. rough idle on a hot start with the CTS that won't throw a code)


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## RichieMax (Feb 22, 2016)

Ty for the great input. They did Change the crank shaft. 
Also over the last year I have seen the memory setting of the side view mirrors, sunroof, seats , and steering wheel also stop working fully. It seems like the steering wheel and seat and side view mirror all try to go back it up and down for the memory but stops after half way or not at all sometimes. But tgey all work normal with switches except rare occasions. They seem to be a little better since they did some work with the ecm. 
I'm not sure if that helps or is a sign as well.
So in your opinion it's the heat sensor, Iacv but also the ecm? 
I'm calling my mechanic and asking him if he did the Iacv already. I have been going for 30 yrs, he's a good guy and good mechanic . He just seems stumped among his other employees. He gave me all my money back because of how long me and my family have been going to him. So I'm just trying to figure it out before bringing it to the dealer . Tgey wants so much money .


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