Idle Air Control valve.

[QCtech]

My 2003 Path have idling problems. The gas pedal needs to be pressed down to start it initially or it will just start and then die. After the engine is warm, it would stay idling at around 1000 rpm, but sometimes it will idle lower than that if you are driving and suddenly come to a stop. I have read in this forum how the IACV can toast your ECM and produce this problem, but for what I can see on the manual and the parts catalog, the 2003-2004 models have no IACV. It only have the throttle chamber. There are completely different regarding this, so I dont think that anything would be frying my ECM if there is not IACV. Im going to start for the easy part and change any fuel filters, but I think the guy that sold it to me already have done it , so I dont know what this idle problem can be. If anyone cares to chime in some suggestions they would be greatly appreciated. Thanks.

[atraudes]

I'm just kind of spitballing here because I'm not super familiar with the 03-04 throttle bodies, but I found this idle air control valve that's supposed to fit your year. Can you confirm that you have this part somewhere? If so, I'd replace it. Based on what you're describing it sounds like the culprit, and for only $35 I'd be willing to give it a shot. You'll probably want/need a new gasket for it as well.

[QCtech]

Thanks a lot. I tried to find that part anywhere on the 2003 part catalog and in the service manual to no avail. It showed up for a Ford and it even says it amazon that it fits my path , but is nowhere to be found. In the 2003 the IAC seems to be part of the trottle body and actuated by a big electrical unit on the side. I searched all the catalogs of nissan and they dont show it for the 2003. I will keep searching and use that part no you gave to to cross reference. I will change the fuel filter probably tomorrow and clean the throttle body and let you know how it goes. Thanks again.

[atraudes]

It's totally possible Amazon's just making noise and doesn't know what it's talking about. It was showing the 01-02 IACVs as well. I did some more searching and other sites are also showing the 01-02 IACV model which we know isn't right. Take a look in the FSM and see if there are any testing procedures for your throttle body (I'm now guessing there is no IACV; it probably just cracks the throttle to regulate airflow). If you end up getting a new throttle body you would probably do fine with a used unit since this type of failure doesn't seem to be too common.

You could also pull the throttle body out and give it a good cleaning. Carbon buildup can block airflow when the valve is closed. Again, sort of a guess, but a good elimination step.

[QCtech]

I will be doing the cleaning etc, but so far what I have gathered from the Service manual and other forums is that the 2003 dont have an independent IACV , and it is built in on the throttle body on that big electronic box on the side, since it is fly by wire. That left me with only the option of removing it and cleaning it very carefully and also with changing the MAF if cleaning dont solve the problem.What seems to be the worst is the relearning procedure, as I see many people and even some dealers having problems with it, but mostly it seems 2001-2002 with the IACV. That one seems to fry some chips inside the ECU and then you have to repair the ECU to be able to fix the rest, even if you change the IACV, so I am glad that this one dont have the IACV because I would think that it wont be able to fry the ECU so easily. Thanks and I will repost when I find and fix the trouble.

PD: Even Rock auto shows like the 2003 uses the IACV , but this is wrong, so it leads a lot of people to major confusion. The IPC is more complete in showing that the 2003 dont use the IACV. The throttle body on the 2003 is also of a different size (tube diameter looks bigger), so that would also be a good way of knowing which one is installed. Hope this helps other people with the same problem.

[QCtech]

I tried some cleaning today, very lighty with spray, but the problem persist. I read the correct rpm with torque app and my idle is perfect around 750, but the problem is always when I start it, it tries to turn off unless I hit the gas pedal. After it revs up it stays on mostly. I think the cleaning helped a little bit, but there is a lot of dirt and tar on the throttle body. I might have to take it out and clean it better.

[Kev90]

I just removed my intake manifold and you can see the amount of gunk that is in it even after running seafoam in the spray can through it. I think the seafoam did a good job cleaning 1/3 of the manifold. This high def photo is the underside of the Upper Intake Manifold and the clean section is right behind the throttle body.

[QCtech]

Just wow. I wonder how mine looks inside with 271000 miles. I dont know if the difference between the 2001-2002 model with the IACV and mine without it would make any impact on this. When I dropped my oil pan my engine had almost no gink inside or in the pan, which surprised me because of the high milleage. I could not find any history of an engine change in my pathy at the dealer.

[veilseven]

QCtech, any chance you have luck solving your idle issues? I'm right in the middle of a similar thing on our 2003 pathfinder. While on a road trip I ordered a IACV (oops) and then realized there isn't one on the 2003s. Cleaned the MAF, cleaned the throttle body, and didn't have much luck. Mine seems to only stumble when heat soaked. So, I'm in the middle of doing the teardown to address PCV, swirl valve screws, plugs, and engine temp sensor.

Just curious if you had any breakthroughs with yours

[pieleapulii]

Hi everybody,
Does anyone know the torque specs for the IACV housing? I want to change the gasket, but can't find a torque spec for this thing anywhere in the FSM or elsewhere - I've tried searching seemingly everywhere - so hopefully someone on here can help me out.
Thanks a lot, and all the best