# 89 ga16i - where are the tps and iacv located?



## Tilt (Jun 29, 2004)

I dont own the car. I'm helping out a friend, so sorry if these are pretty obvious questions. 

Can someone please let me know what the tps and iacv look like and where they are exactly located on an 1989 automatic sentra ga16i (it's got a carburated style setup)? 

The cars got some idling problems - idle fluctuates and feels like it wants to stall out. I have the procedure, and I know you are supposed to disconnect the tps before you adjust idle. Im just not sure where it is.

I also read on this board that cleaning the iacv helps with surging idle. Id like to know where it is located on a carburated setup (or if it even has one).

thanks in advance and happy 4th of july!


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## Nismo1997 (Dec 26, 2003)

Tilt said:


> I dont own the car. I'm helping out a friend, so sorry if these are pretty obvious questions.
> 
> Can someone please let me know what the tps and iacv look like and where they are exactly located on an 1989 automatic sentra ga16i (it's got a carburated style setup)?
> 
> ...



tps i would beleave it would b on throttle body like on ne other car


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## minute rice sentra (Mar 21, 2003)

The GA16i has throttle body injection not carb, and I don't know of any iacv valve??? Maybe it's the aac or ficd valve? They are located on the back of the throttle body.


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## Tilt (Jun 29, 2004)

im still not sure where the tps is. ive looked next to and around the throttle rotor and im not finding it.


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## Tilt (Jun 29, 2004)

this is just not my day. 

can someone please describe where the idle adjust screw is located? i read that there is a plastic cap covering the adjust screw but i cant find it anywhere.


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## Mervic (May 1, 2002)

Usually the TPS sensor is disconnected to change the base timing. The GA16i has no IACV unit or Idle AIr Control Valve. You will find these on CA, GA16DE and SR engines to control idle during cold engine operation. What the GA16i have is the IAA unit which composed of FICD (fast idle control device) solenoid valve, AAC (auxillary air control) valve and the idle-up solenoid. You would see this unit at the back of the TB. I would also check the EGR valve for normal operation since when its faulty or clogged, the car will have erratic idle. Check the MAF sensor if working or not.


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## Tilt (Jun 29, 2004)

Thanks Mervic. We ended up getting a chilton manual, and everything you said is on the money. 

The car seems to run ok from a cold start. Once it is warmed up it stalls out. When it's started back up it stumbles and dies again. Have to give it gas for a bit before it starts up. When it does the accel is erratic, feels like it's stumbling and when you let of the gas, once again it stalls out. We have to wait for it to cool down before it can start fine again.

We've messed with the spark plugs, wires, distributor cap and rotor, fuel filter, and ignition timing. Also have checked the ecu for codes -- it blinks 55 so I believe that means it's ok. 

Ive read the chilton and it says the idle is controlled by the ecu. Does it completely? or is there a way to manually adjust the idle? 

Does this sound like a common or known problem with this particular model? 

tia



Mervic said:


> Usually the TPS sensor is disconnected to change the base timing. The GA16i has no IACV unit or Idle AIr Control Valve. You will find these on CA, GA16DE and SR engines to control idle during cold engine operation. What the GA16i have is the IAA unit which composed of FICD (fast idle control device) solenoid valve, AAC (auxillary air control) valve and the idle-up solenoid. You would see this unit at the back of the TB. I would also check the EGR valve for normal operation since when its faulty or clogged, the car will have erratic idle. Check the MAF sensor if working or not.


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## Mervic (May 1, 2002)

Check the coolant level. The fast idle cam is a wax type which connected to the dashpot, uses the coolant to control how much the movement of it. You can see the small coolant hoses near the bottom of the throttle body. I've never had any idling problem with my car. The idle adjusting screw can be adjusted manually. Refer to your Chilton manual on pages 1-57 to 1-58 for the proper procedure. Hope you fix the problem.


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## Tilt (Jun 29, 2004)

Thanks for the help. 

The main problem ended up being corroded contacts on the MAF. It was causing it to stumble and stall. Cleaned it up and tinkered with other parts of the car and now runs like a champ. 



Mervic said:


> Check the coolant level. The fast idle cam is a wax type which connected to the dashpot, uses the coolant to control how much the movement of it. You can see the small coolant hoses near the bottom of the throttle body. I've never had any idling problem with my car. The idle adjusting screw can be adjusted manually. Refer to your Chilton manual on pages 1-57 to 1-58 for the proper procedure. Hope you fix the problem.


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