I've never cleaned this valve out. For those who have cleaned it, did you actually find it plugged up? I'm not having any problems with my idle, so I'm wondering if it's worth doing just as preventive maintenance. I don't want to mess with a good thing.

 

Mine had gunk in it. I cleaned it.

Often you dont notice a problem until its gone.

 

i did mine just for the he** of it but my idle was a little high (around 900). it gets carbon build up in it and i just used an old tooth brush and some carb cleaner. after cleaning it my idle became a little low (600). idk if its really preventive maintenance but i just like the idea of having a clean engine.

 

Cleaning it out can only help it, unless you something wrong, but it's pretty straight forward...

Mine had alot of **** in it, but my Max had over 150k on it when I did mine.

P.S. Dude the Max in the above pic looks like it's been to hell and back... with me driving...boosted...offroad

 

what do you call ...... gunk ?


Dont forget the gasket

I did my TB at the same time

 

Thanks all. Man....great pics...exactly what I needed to see. Man...that thing was nasty!

 

have you noticed any difference after cleaning it ??

 

of curse, idle is better, stronger, mpg rose due to the clean TB, throttle response is slightly smoother but thats also cause i also tightened the TB cables at the same time

overall yes my idle was jumpy before, very slightly it would oscillate, but not anymore

 

thanks..

what is the first gasket for? the smaller one

 

ok... the ONLY way to clean this valve is to actually take it apart from the housing and cleaning the plunger by its self... so u need to remove the 2 gold screws and take it apart gently... then remove the little plunger and gently clean it with brake clean or what ever you wanna use..

you also need to clean the plungers for both the purple connector and the pink one...

again u need to take then out and clean JUST the plunger..

Just spraying the part that is in the picture above doesnt do SHI.T... you need to take it apart and clean it.. cuz after all carbon gets built up on the plunger and keeps the valve open causing the hight idle...

your welcome... good luck...

 

Throttle body gasket

 

High idle ?

I think it causes low idle cause thats what my problem was, it would idle at 550 rpm and wobble up and down just slightly trying not to get below 500, and i heard it easy to mess up the IACV when you take all those things off. and my idle improved so it worked for me,

i would not wanna be down the hole $600 dollars for a new IACV
http://catalog.eautopartscatalog.com...2b2187b0529cfa

 

I just replaced my IACV after getting the #25 DTC several times and also noticing my idle getting flakier and flakier. Piece of cake to replace - took about 15 minutes.

Dealer price for the valve was $175.97 and the gasket was $1.97. After seeing the carbon in the old valve, I figure a cleaning might have fixed the problem. But replacing really wasn't too expensive, especially considering I've had the car 13 years (188K miles)

 

To clean IACV valve is easy and cheap but it will bring a great result.
Thanks.

 

I am thinking of cleaning mine IACV but at the same time I don't want to see any of the SES light. I also noticed that my idler would flucate in traffic when I am at the light or slowing down it drops too about 600-700rpms. My point is could I clean the IACV when the battery is disconnected and will that avoid the check light.

 

yeah as long as the battery is disconnected you won't get a light. Actually even if it is connected you won't get a light. You shouldn't have the car on cleaning the IACV. As stated before to clean it well it needs to be removed. Not spraying **** in it or at it. Take things apart and clean or don't do it at all.

 

how is it easy to screw it up?

mine idles fine at 141k miles but i just wanna clean it for the hell of it

 

how much was that IACV gasket?

 

$5.48+ tax canadian from the dealer
the TB gasket was 4.85

total with tax i paid 11.78 for both

Due to corruption reasons dealers charge more here in Canada than compared in the US

And btw it was never written anywhere that the iacv has to be taken apart for it be cleaned better, if i knew this i would obviously do it, now im not gona bother anymore, i got there car where i want it, its functioning to my liking and im going to leave it at that.

Maybe the stickies should have been more detailed

 

The reason I asked because I have heard people complaining on how they have had the SES light on now when they cleaned it and on one of the threads stated that you have to remove the battery connectors then go from there.

it's not like it's either or kind of answer theres only one answer.
I know that spraying is not going to do anything of course i am gonna have to take it apart and clean it but the SES light gets me worried.

 

To all those worrying:

Just do it. There really arent many small, sensitive or damageable parts in it. Springs, plunger things, etc...I damaged more screws than I did parts. Put it this way, really the only way to hurt it is to try to hurt it, or install something back in wrong. Its simple and not very risky.

Use TB cleaner, tooth brush, paper towels and 15 minutes.

 

Mine too.

However, its a steady 1600 while i coast, but if i stop for a couple seconds, it goes down to 1100.

There are no idle control screws on maximas right? (sorry, havent had mine for long)
I looked in the Chiltons manual, and couldnt find any.

Am i missing something, or will i have to take it in for a tune up?

 

Cleanig the TB really helped alot i am yet to clean the IACV i will surely let you know the results then

 

IF you're getting 1100 while stopped (fully warmed up), then that's waay off the charts. There IS an idle adjustment screw. It's a black, plastic screw on the IACV.

 

Check the FSM for the correct way to adjust your idle RPM.

 

+1

 

Where are the two gold screws you mention? Can you see them on the picture above?

 

Thanks.

After cleaning the IACV and TB, my idle steadied up.

I must have overlooked that screw. I tightened it, and now the idle when warm is at about 700. 1100 while coasting.

Thanks for the help!
Zac

 

that's sounds good now You can still raise the idle to about 750rpm, it'll idle just a bit smoother.

 

Is there a thread with instructions on how to clean the TB and IACV? It would be nice to have it with pictures. Thanks guys for helping out.

 

you don't need instructions. its just a couple of nuts and bolts and a TB cleaner.


read the stickies newb

 

the screws are NOT the ones in that pic.. they are the ones that hold the valve to the body.. they are kinda tuff to remove so get a good #2 Phillips screwdriver..

 

Hi, Im planning to do this this weekend. Anyone have any more pics of this of cleanning it throughly.

 

TO AL NEWBS, FAMILIARIZE YOURSELVES WITH THE FAQ THREAD!!!! Andrei's pics are more than enough!

 

Guys there is hours of reading you can get from the FAQ and the rest of the stickies, but for those who are just incapable of such small effort here is a teaser pic and some instructions.

These instructions were created by someone else, i am sorry i forget who, but the credit is not mine, but thats what i used - its easier to do with the TB off the engine but you dont have to do it that way, i take no responsibility if you blow up your engine... ;-)





TB AND IACV
How to clean TB and IAC Valve
________________________________________


Tool required:
ratchet
10m socket
12mm socket
flathead or 8mm socket
pliers or vise grips
1 can of Throttle Body cleaner
1 can of Carb cleaner (I find Berrymans B12 to work fastest)
new throttle body gasket
new IAC Valve Gasket (dealer only)

1) disconnect battery. unclip airbox, unplug MAF Sensor, use pliers to slide clamps holding hoses to airbox down and slide off hoses, use flathead or 8mm socket to loosen clamp holding air tube to throttle Body, remove 10mm socket on side of airbox holding it down and remove air intake assembly.

2) move throttle to fully open position, lift throttle cables one at a time forward and wiggle out of the TB (towards the left of the TB). Unplug 2 Throttle Position Sensor Plugs.

3) remove the 4 12mm bolts holding the TB to the plenum

4) on the bottom of the TB there will either be 2 or 3 hoses attatched. use pliers to slide clamps down and remove hoses. make sure your radiator cap is still on or engine coolant will start to flow out. If hoses have seized on, use flathead to pry the top and break the seal.

5) Remove throttle body. scrape old gasket from both surfaces. clean entire buttefly plate (both faces) and cylinder. there should be no black when done. use only tb cleaner as carb cleaner will remove teflon coating which can later lead to faster corrosion and/or deposit formation

6) locate IAC Valve (triangular unit bolted to drivers side of the plenum right in front of the firewall with a large hose that was connected to the air intake assembly) unplug all 4 plugs.

7) remove 10mm bolt holding EGR Temp Sensor plug to the IAC Valve. (hard to see so you may have to feel around the firewall side for it) It is the only plug of the 4 not directly attatched to the IAC Valve body

8) remove 3 12mm bolts holding IAC Valve to the plenum and remove IAC Valve. Remove old gasket (no need for scraping as it is a metal gasket).

9) spray/wipe the entire inside of the triangular face clean. Spray the inside of the brass housing clean of all deposits. spray base of Idle screw clean to ensure no carbon deposits remain. Be liberal with the spray.

10) replace gaskets and reassemble in reverse order. make sure when attatching the air tube to the TB you tighten the clamp. a loose clamp = a small vacuum leak that probably cant be heard but will be felt (high idle).

before reassmebling, some like to spray remaining tb cleaner/carb cleaner into the plenum to clean it up. This is usually a waste of time since oil coming from the PCV will quickly muck it up again but pooled cleaner may help clean downstream intake when you start it back up. not enough to make a bg difference but hey. If you do this, dont be alarmed by the blue smoke at startup (oil and sludge being burned off). Start the car, take it for a short run to blow any remaining cleaner out and you are done.

 

thanks alot andrei

 

Cleaning the IACV, TB, and MAF, as well as lowering my idle made my MPG go up about 3 mpg on half a tank.

 

do u have to replace the gaskets?

 

YES you do have to replace both gaskets

unless you want air leaks and crappy idle and want to go back, take everything apart and replace the gaskets then ?

spend the 10-20 dollars on gaskets dont cheap out for that ok ? and also

Dont listen to anyone here who will tell you they re-used the gaskets, the metal gasket for the IACV is a crush gasket, as you tighten the 3 bolts it spreads making sure no air leaks, and i think its kinda obvious from the above pictures why you have to replace the paper gasket on the TB !!!!!

Just go to the dealer and ask for the throttle body gasket and idle air control valve gasket for your year (should be the same 95-99 tho and should look like the pic i provided above)

 

Thanks alot Andrei, I will buy this tomorrow at the dealer shop