# My car soulds like it Idles up and down



## Stanza90 (Aug 21, 2005)

hello..im new to all this so please help me out..i got a 90 nissan stanza that feels like it idles up and down and feels like it wants to shut off at times ive changed the plugs, wires, dist. cap and rotor..i dont know what else to do?


----------



## de2r (Aug 6, 2005)

Have you checked the level of your coolant? If you're low, or have an air pocket it will effect your idle. Top up and burp the system if nessesary and see if that settles things.


----------



## Gsolo (Sep 11, 2003)

sounds like the engine is hunting. theres a few possibilities...the most likely is a lazy O2 sensor. another possibility is a tired MAF.


----------



## 92stanza (Sep 4, 2005)

check your TPS (throttle position sensor) and idle air control valve


----------



## Stanza90 (Aug 21, 2005)

92stanza said:


> check your TPS (throttle position sensor) and idle air control valve


THIS IS GONNA SOUND STUPID BUT WHERE IS THE THROTTLE POSITION SENSOR AND IDLE AIR CONTROL LOCATED?


----------



## de2r (Aug 6, 2005)

92stanza said:


> check your TPS (throttle position sensor) and idle air control valve


 

I would suggest running your codes first before removing anything. Under your driver's seat there is a diagnostic computer. On the right there is a switch. Procedure is as follows:

1.) Make sure it is turned OFF. 
2.) Turn your key in the ignition to ON. 
3.) Make sure that the 2 inspection bulbs (1 red, 1 green) stay on - this is a bulb check. 
4.) Now turn the switch on the computer to ON. The bulbs will flash out the codes for you. Example: 1 red flash + 2 green flashes = Code 12. Air Flow Meter.

Codes:

12 = Air Flow Meter
13 = Water Temperature Sensor
21 = Ignition
22 = Fuel Pump
23 = Throttle Valve Switch
31 = Idle Control System
32 = Start Signal
41 = Air Temperature Sensor

44 = System is operating properly

When finished retrieving codes, disconnect negative cable on your battery for at least 15 seconds. Reconnect cable and turn switch on computer to OFF. 

Now you can pin-point any faults.


----------



## Stanza90 (Aug 21, 2005)

de2r said:


> I would suggest running your codes first before removing anything. Under your driver's seat there is a diagnostic computer. On the right there is a switch. Procedure is as follows:
> 
> 1.) Make sure it is turned OFF.
> 2.) Turn your key in the ignition to ON.
> ...


well i looked for the diagnostic comp. under the seat and couldnt find anything


----------



## 92stanza (Sep 4, 2005)

Stanza90 said:


> well i looked for the diagnostic comp. under the seat and couldnt find anything


The ECU on a 90-92 stanza is located in the back of the center console under the radio you can get to it by the passenger side


----------



## Stanza90 (Aug 21, 2005)

thanks..i wont hurt anything will i? could it be that the fuel injectors have gone bad?


----------



## guitarsage (Mar 26, 2005)

I seen this post, and I just had the same problem with my altima... i went thru the same things, and replaced the same things you did. I put some Chevron Techron fuel injector cleaner and put in a half a tank of gas and after I about ran all the gas out my problems were fixed and it is better than it was before it screwed up nice and smooth idling. It might not help any, but its a cheap thing to try. You can get a bottle at walmart for like $6


----------



## 92stanza (Sep 4, 2005)

Try to spray some Throttle Body Cleaner into the manifold and see if that helps


----------



## Stanza90 (Aug 21, 2005)

what manifold? the exhaust manifold?..sorry im just learning about cars so im not very familiar with this kinda talk..i appreciate all of you guys help thanks


----------



## Stanza90 (Aug 21, 2005)

well i ran the diagnostic computer and first off the bulb check failed...only the red one turned on so where do i go from there?


----------



## 92stanza (Sep 4, 2005)

Stanza90 said:


> what manifold? the exhaust manifold?..sorry im just learning about cars so im not very familiar with this kinda talk..i appreciate all of you guys help thanks


the intake manifold just remove the air duct from the throttle body and spray some Throttle Body Cleaner into it make sure not to spray too much because you might over flood it, just spray a bit at a time and run the engine


----------



## de2r (Aug 6, 2005)

Stanza90 said:


> well i ran the diagnostic computer and first off the bulb check failed...only the red one turned on so where do i go from there?


Unbolt the negative battery cable for at least 15 seconds. Re-connect it and try the diagnostic procedure again.


----------



## rt76 (Aug 24, 2005)

Stanza90 said:


> hello..im new to all this so please help me out..i got a 90 nissan stanza that feels like it idles up and down and feels like it wants to shut off at times ive changed the plugs, wires, dist. cap and rotor..i dont know what else to do?


My 92 is doing the same thing and I've changed the Mass air sensor which is what the codes from the computer told me to do but it didn't help. Next it says change the ECCS relay and I can't find that, anybody else know where it is.


----------



## Stanza90 (Aug 21, 2005)

well i went ahead and tried doin the diagnostic procedure..and still theres only the red light going on...i think the green is busted or something...so my problem is once again that when the car comes to a stop..the rpms go up and down..from 1 to 0 and feels like it wants to cut off..what should i do?


----------



## 92stanza (Sep 4, 2005)

how does it feel when your driving, does feel like it doesnt want to pick up?


----------



## rt76 (Aug 24, 2005)

Stanza90 said:


> well i went ahead and tried doin the diagnostic procedure..and still theres only the red light going on...i think the green is busted or something...so my problem is once again that when the car comes to a stop..the rpms go up and down..from 1 to 0 and feels like it wants to cut off..what should i do?


My 92 stanza only has one red light that gives short and long flashes. It will give long flashes first and then short flashes. The number of long flashes will be the first number of the code and the number of short flashes are the second number of the code. For example: my car was giving one long flash and two short flashes and that's a code of 12. 
By the way, I finally got mine to quit revving up and down. I took the front of the throttle body off, the part with the butter fly valve and cleaned it and also blew out the vacum line on the bottom of that assembly, that goes to a little hole that's right under the butter fly valve and I think that was stopped up.
Here are some other things that will make it rev up and down: Bad Mass Air Sensor, vacum leak in the big hose from the filter to the throttle body. A vacum leak anywhere on the 3 smaller hoses that fit to that big air hose.


----------



## Stanza90 (Aug 21, 2005)

well it feels fine when im driving it..well at first it hesitates...when i give it gas it wont take off itll take like a minute before it goes fast..before i would stomp on the gas and it would take off...and when i come to a stop the rpms drop all the way to about 0 and wants to shut off so i have to be giving it gas so it wont turn off....im glad you got your car fixed..hopefully i can eventually find out whats up with mine..


----------



## 92stanza (Sep 4, 2005)

try doing this it might help, go buy some throttle body cleaner and remove the air duct from the throttle body, spray some Throttle Body Cleaner into it make sure not to spray too much because you might over flood it, just spray a bit at a time and run the engine


----------



## rt76 (Aug 24, 2005)

92stanza said:


> try doing this it might help, go buy some throttle body cleaner and remove the air duct from the throttle body, spray some Throttle Body Cleaner into it make sure not to spray too much because you might over flood it, just spray a bit at a time and run the engine


what 92 stanza said may help. However, when I sprayed my throttle body, I broke some trash lose and it got down in that tiny air duct right under the butterfly valve and screwed everything up. I would try it anyway though. Also when I took my air hose off from the filter to the throttle body, it was dry rotted and it ripped and a new one cost me $100. I might add that nissanpartscheap.com is a great place to buy parts when only nissan will do, there about 30% cheaper than the dealer and have fast service.


----------



## Stanza90 (Aug 21, 2005)

i was talking to this sales man from carquest and he told me to check the throttle position sensor...he thinks that might be it..im gonna go ahead and try spraying that stuff..ill keep yall posted on what happens..i apprecitate all of yalls help..thanks


----------



## Stanza90 (Aug 21, 2005)

on friday i was trying to get to work, i turned the car on, drove off-i thought it was working fine UNTIL about 4-5 minutes into my drive it kept trying to shut off...i tried to give it gas and it didnt even want to move really..it was going real slow even though i was hitting the gas pedal..i had to hold the brake and had to be giving it gas so it wouldnt shut off at the stop light....the RPM needle was not moving at all when id give it gas...luckily it didnt leave me stranded again..had to turn back home and get my truck..do any of u all think it might be the throttle position sensor, i checked it out and about 1/4 of it was melted...


----------



## 92stanza (Sep 4, 2005)

how does the car feel when its in idle? does it hesitate or is it still? also check to see if there is any oil around the distributor


----------



## Stanza90 (Aug 21, 2005)

what would the oil in the dist. cap do? im gonna change out the throttle position sensor to see what that does..


----------



## de2r (Aug 6, 2005)

Changing out the TPS is a must now that it's melted but now you're faced with why it melted in the first place.


----------



## mchoffa (Sep 3, 2005)

I can't think of a reason the TPS would melt... bad wiring? maybe blocked exhaust? I don't know a whole lot about how cars work, but I know my stanza really ran rough before I got a new cat converter and muffler... I may be way off but I would say it is worth looking at everything...


----------



## Stanza90 (Aug 21, 2005)

how difficult is it changing out the cat converter? is it pretty complicated..?


----------



## 92stanza (Sep 4, 2005)

i would get it checked out at a local muffler shop to see if it really needs replacing, is your car still idleing up and down?


----------



## Stanza90 (Aug 21, 2005)

it sure as hell is...haha..i took off the tps and im gonna replace that to see what it does


----------

