# Car cuts off



## Cello (Sep 28, 2004)

when I'm driving and I try and stop or downshift my sentra acts as if it wants to cut off and sometimes it actually cuts off don't know where to start troubleshooting need some help here peeps.


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## Hydrolock (Feb 18, 2005)

Cello said:


> when I'm driving and I try and stop or downshift my sentra acts as if it wants to cut off and sometimes it actually cuts off don't know where to start troubleshooting need some help here peeps.


Cutsoff=stall?


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## Cello (Sep 28, 2004)

Hydrolock said:


> Cutsoff=stall?


It will cut off and I have to start it back up, not stalling, what do you mean by stalling.


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## Catman (May 21, 2004)

When the engine stalls, it shuts off. Sounds like what you are describing. Since I do not know the full details and maintenance of the car, I am going to suggest a few things. Clean the throttle body/throttle plate. I cleaned mine with an old tooth brush and a can of Throttle Body Cleaner from Auto Zone for about $3.00. Also, I cleaned the Idle Air Control Valve. It will adjust the engine idle to varying conditions. But, it works in conjunction with throttle body. Also, changing the fuel filter if it is been a while. I do mine every 30,000 miles. For about $20.00 my car went from stalling and hesitating, to having most of those symptoms gone. If your car has not been tuned-up recently,( Air Filter, NGK plugs, Cap, Rotor, PCV valve), then it may be time for those things also.


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## Partyboy25 (Jan 27, 2005)

mine started doing this and now the engine is dead. The mechanic said I through a rod, so if I were you I would get it checked out. Now im on here looking for a new motor :waving:


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## Hydrolock (Feb 18, 2005)

Catman said:


> When the engine stalls, it shuts off. Sounds like what you are describing. Since I do not know the full details and maintenance of the car, I am going to suggest a few things. Clean the throttle body/throttle plate. I cleaned mine with an old tooth brush and a can of Throttle Body Cleaner from Auto Zone for about $3.00. Also, I cleaned the Idle Air Control Valve. It will adjust the engine idle to varying conditions. But, it works in conjunction with throttle body. Also, changing the fuel filter if it is been a while. I do mine every 30,000 miles. For about $20.00 my car went from stalling and hesitating, to having most of those symptoms gone. If your car has not been tuned-up recently,( Air Filter, NGK plugs, Cap, Rotor, PCV valve), then it may be time for those things also.


Yeah what he said. I'd also my sure your timing is correct.


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## Cello (Sep 28, 2004)

Well I replaced Cap and rotor, also spark plugs and wires just bought a PCV valve yesterday from auotzone and I"ll be replacing it sometime this weekend as far as cleaning the throttle body and Idle Control Valve haven't touched them neither of them but I will be doing it this weekend. How do I go about cleaning the both of them?


Catman said:


> When the engine stalls, it shuts off. Sounds like what you are describing. Since I do not know the full details and maintenance of the car, I am going to suggest a few things. Clean the throttle body/throttle plate. I cleaned mine with an old tooth brush and a can of Throttle Body Cleaner from Auto Zone for about $3.00. Also, I cleaned the Idle Air Control Valve. It will adjust the engine idle to varying conditions. But, it works in conjunction with throttle body. Also, changing the fuel filter if it is been a while. I do mine every 30,000 miles. For about $20.00 my car went from stalling and hesitating, to having most of those symptoms gone. If your car has not been tuned-up recently,( Air Filter, NGK plugs, Cap, Rotor, PCV valve), then it may be time for those things also.


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## Cello (Sep 28, 2004)

Is there another name for the Air Idle Control Valve if so can you please give it to me I'm looking in the Haynes manual and can't find it, if you have the same manual give me the chapter and how do I clean the throttle body/plate and Air Idle Control Valve never done this before.


Catman said:


> When the engine stalls, it shuts off. Sounds like what you are describing. Since I do not know the full details and maintenance of the car, I am going to suggest a few things. Clean the throttle body/throttle plate. I cleaned mine with an old tooth brush and a can of Throttle Body Cleaner from Auto Zone for about $3.00. Also, I cleaned the Idle Air Control Valve. It will adjust the engine idle to varying conditions. But, it works in conjunction with throttle body. Also, changing the fuel filter if it is been a while. I do mine every 30,000 miles. For about $20.00 my car went from stalling and hesitating, to having most of those symptoms gone. If your car has not been tuned-up recently,( Air Filter, NGK plugs, Cap, Rotor, PCV valve), then it may be time for those things also.


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## Catman (May 21, 2004)

Here is how I cleaned the Idle Air Control Valve:

http://www.nissanforums.com/showthread.php?t=63315&highlight=IDLE+AIR+CONTROL+VALVE+pictures

The main thing was cleaning carbon from the part exposed to the intake. Yes, it is listed as Auxiliary Air Control (AAC) Valve in Haynes. Actually, they have some very good pictures in Haynes and intructions. I was using Alldata as a reference. I think the AAC is part of the entire IACV unit that you have to remove as part of the cleaning.

All I did with the throttle body is remove the air intake snorkel and put it on top of the throttle body. In order to do this I had to remove a smaller hose coming out of the valve cover that is also connected to the snorkel. That gave me enough room to spray the throttle plate. Opened the throttle by hand, and stuffed a rag under the throttle plate while cleaning. Also, I had extra rags or paper towels to absorb the stuff that ran out. I did this on a cold engine with the engine off, to keep the crud from going through the combustion chamber. I did this until fluid was clear. I know a lot of people like to remove the throttle body, but, what I did got the job done.


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## Cello (Sep 28, 2004)

Thanks for the help and the pictures I'm going to autozone tomorrow and get what I need if I need any more help I'll just email.


Catman said:


> Here is how I cleaned the Idle Air Control Valve:
> 
> http://www.nissanforums.com/showthread.php?t=63315&highlight=IDLE+AIR+CONTROL+VALVE+pictures
> 
> ...


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## Cello (Sep 28, 2004)

Well I cleaned the valve and the throttle body and now the car turns on idles very high and then proceeds to cut off. I'm stuck don't know what to do.


Catman said:


> Here is how I cleaned the Idle Air Control Valve:
> 
> http://www.nissanforums.com/showthread.php?t=63315&highlight=IDLE+AIR+CONTROL+VALVE+pictures
> 
> ...


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## Catman (May 21, 2004)

Are you sure you have no vacuum leaks? Assuming everything was put back the way you found it, with no leaks (I have done that), it would be good to test the Auxiliary Air Valve/IACV and fast idle solenoid. Haynes has instructions that may be better than what I posted. If bad, it may need to be replaced. Since things changed after cleaning, it may be good to focus on the things you worked on. One more thought, the throttle position sensor is also a part of the loop of information to determine idle. You could test that if the Auxiliary Air Valve and fast idle solenoid are OK. Hopefully, you have an multi meter. I am limited in what I can recommend, since my experience is limited. Maybe others can chime in.


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## Cello (Sep 28, 2004)

I don't know if I have any vaccum leaks, how can I tell.


Catman said:


> Are you sure you have no vacuum leaks? Assuming everything was put back the way you found it, with no leaks (I have done that), it would be good to test the Auxiliary Air Valve/IACV and fast idle solenoid. Haynes has instructions that may be better than what I posted. If bad, it may need to be replaced. Since things changed after cleaning, it may be good to focus on the things you worked on. One more thought, the throttle position sensor is also a part of the loop of information to determine idle. You could test that if the Auxiliary Air Valve and fast idle solenoid are OK. Hopefully, you have an multi meter. I am limited in what I can recommend, since my experience is limited. Maybe others can chime in.


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## Catman (May 21, 2004)

Sometimes you can here a hissing sound. Look for vacuum hoses that have cracks or that are loose. Since you removed the IACV unit for cleaning, it is important that it made a good seal. Did you use the old gasket? Is it torqued properly? That may not be the problem, just something to check. 

Since things changed after removing the IACVU (idles high, then cuts off), it seems you are getting close to your problem, since the fast idle control device(FICD) is part of the the IACV unit. I do not see how the cleaning the throttle body would cause high idle, unless something is binding. In your Haynes manual it shows how to apply voltage to test the solenoid on the FICD. Just be careful not to shock yourself.  (Something I might do to myself when in a hurry). I have a feeling it is not working properly, at least that is one of the first things I would test.


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## Cello (Sep 28, 2004)

Hey I see you say soething about a gasket guess what when I removed my AAV/IACV the gasket was missing so I went to the nissan dealership and order one it should be in tomorrow sometime so I'll start there and see what happens and thank for all your help again.


Catman said:


> Sometimes you can here a hissing sound. Look for vacuum hoses that have cracks or that are loose. Since you removed the IACV unit for cleaning, it is important that it made a good seal. Did you use the old gasket? Is it torqued properly? That may not be the problem, just something to check.
> 
> Since things changed after removing the IACVU (idles high, then cuts off), it seems you are getting close to your problem, since the fast idle control device(FICD) is part of the the IACV unit. I do not see how the cleaning the throttle body would cause high idle, unless something is binding. In your Haynes manual it shows how to apply voltage to test the solenoid on the FICD. Just be careful not to shock yourself.  (Something I might do to myself when in a hurry). I have a feeling it is not working properly, at least that is one of the first things I would test.


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## PSr_SEX-R (Feb 1, 2005)

Cello said:


> when I'm driving and I try and stop or downshift my sentra acts as if it wants to cut off and sometimes it actually cuts off don't know where to start troubleshooting need some help here peeps.


try your fuel filter first. my car did the same thing. it would idle fine but when you floor it, it shuts off. chage the filter before you try messing around with anything else, fuel filter is cheep and easy to change

i just glanced over the posts so if you already changed it sorry for telling you to do it again


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## Catman (May 21, 2004)

> Hey I see you say soething about a gasket guess what when I removed my AAV/IACV the gasket was missing so I went to the nissan dealership and order one it should be in tomorrow sometime so I'll start there and see what happens and thank for all your help again.


My gasket was not missing, but very compressed and stuck to the intake side. I took a chance with putting a thin film of High Temp RTV as a gasket. Worked the two times I removed it. It was easy to remove. I just peeled it off. Old gaskets, on the other hand can be a pain to remove. When I had the head rebuilt on my Mazda truck, I learned a lot about gaskets and RTV. I used some RTV on my intake and it leaked like a sieve. Went to the shop manager. He said two flat, clean surfaces will seal without RTV. I skipped the RTV, and it worked fine. I am saying this to make sure you know to clean the surfaces before re-installing them. My favorite is Isopropyl Alcohol and a paper towel or clean rag. Cheap, and odor is not too bad when using. Brake cleaner and other products make me sick. Also, it would be good to use a torque wrench, if you have one. My favorite one is a beam type from Sears that has a range from 0-75 ft lbs. I also have two that are inch pound clicker type, and one that is a foot pound clicker type torque wrench, but have broken bolts. It is harder tell torque. The beam one is limited. It only reads on one side, and you need enough space. Hopefully, the gasket will solve your current problem. It sure would suck in a lot of air if the seal was not good. RTV is good in some applications, but in others all you need is a gasket.



> try your fuel filter first. my car did the same thing. it would idle fine but when you floor it, it shuts off. chage the filter before you try messing around with anything else, fuel filter is cheep and easy to change


I agree changing the filter is important. Mine had about 12,000 miles on it when cleaning my IACVU. But, it was a cheap Purolator one made in China. I was doubtful of quality. Replaced it with a more expensive filter, even though I usually wait till I had 30,000 miles on the filter. In my case the filter did not seem to cause the problem, but it is hard to tell what role it may have played in the overall performance. It is also cheap insurance for the fuel pump and injectors.


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## Cello (Sep 28, 2004)

Thanks for all your help my B13 is back up and running.


Cello said:


> Hey I see you say soething about a gasket guess what when I removed my AAV/IACV the gasket was missing so I went to the nissan dealership and order one it should be in tomorrow sometime so I'll start there and see what happens and thank for all your help again.


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## Catman (May 21, 2004)

That is great!


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