Here's the dirty throttle plate. The black ring around the plate felt like a super tacky glue and it literally felt like it was causing the throttle plate to stick a little. With a toothbrush and some carb cleaner made some short work of it.



All Cleaned...



Here's a slight mod to the front duct to allow some fresh air into the engine bay sirectly into a cold air port on my custom made airbox to be seen later.



Remove coil connector



Then remove the bolt securing the coil



Gently remove



Clear shot to the plug - use shop air to blow out any debris - mine were totally clean as should most.



Carefully remove the stock plug, if you need too spray a small amount of penatrant down in the hole and let sit for a few minutes but be careful not to over do it as you can spray too much and have it drain into the cylinder and cause a hyrolock on startup. I used a small amount because I was wary of the threads on the aluminum heads.



Use spark plug socket to remove plug or use any handy tool to assist.



Stock plug looks ok - good burn - slight pitting due to detonation but no serious signs of impending doom.



New Hotness NGK Iridium IX



Use antiseize on the threads!!!!!



Rear plugs were the biggest pain, but once I founf out the right socket and extension combo to use it was quite easy. It looks nearly impossible but it isn't Nissan/Infiniti left us just enough room back there.



Shot of the gunk build up behind the throttle plate - not too bad for 52K - Notice the vertical hose leading in from the top - that is the PCV line and is where the oil in the manifold is coming from(the brown stuff way back there)



I got ambitious and wanted to see the interior of the manifold. It's pretty nifty in there and I was surprised at the lack of oil built up.



Notive the High Speed air horns at the top that crack open under high rpm WOT conditions. With my custom air filter setup you can clearly hear the switchover and sounds quite cool.







Stay organized with your plugs - looking at them in order can tell you alot of how your engine is perfroming.



Finally the catch can. I literally made this for $6 from a stainless steel water bottle I had laying around the house and using some Stainless steel wool balls from the kitchen and fittings I've had laying around from my years working on Nissans - Only thing it needs is some sort of signt and drain.



Also in an effort to control the black gunky stuff around the throttle plate I installd a clear fuel filter on the opposite side of the PCV system. This side can actually draw air in as well and that could potentially be unfiltered oil misted air from the crankcase of the engine - cost $3.99



Close up of all 8 plugs in order - they all look good to me

I also needed to perform the Accelerator closed position learning procedure, the throttle plate closed position learning procedure, and the Idle Air Volume learning procedure when all was complete. After that the idle dropped right to 650rpm and ignition timing was near dead on!

Driving impressions - after cruising a bit I really started to notice a stronger mid range torque band where the engine would really pull the car out of the hole without much effort. I am assuming this is because the engine is allowing more timing due to the decrease of oil vapor in the airstream allowing for more timing.

Also the driveability is back to better than ever, I no longer have any weird rogue shift delays nor do I have that "on/off" throttle control while coasting Ike I used to have.

I feel that this is more closely how the car drove initially off the lot, it is driving better than ever at the moment. No MPG increases though.

Nice write-up, thanks!

Z

Thanks for the info. I order my oil separator from Jegs saturday. I need to know where to install it. Where on the engine is the PCV valve located and where is the line that goes back to the intake? I will need to put it in line that way since the filter and can come together. I see how you have yours...so does the oil hit the can first then the clean air goes to the filter or vise versa? I dont see how the oil will enter the can from that T point. Shouldnt it be directly in line?

Bad picture with MS paint - but I actually hit both sides of the PCV system. The red indicates hot crankcase air - the blue is what's returning to the intake under vacuum when the throttle is closed

Doing this mod myself will depend on how that filter looks in a few thousand miles. Please do keep us informed on its condition.

Thanks for this!!!

I've put a few hundred - maybe 1k miles on it since - I drive alot - and that filter is clean as a whistle and the catch can, from what I can tell, is near empty because I can't feel anything in there by shaking it around. From what I've heard the larger catch cans collect more moisture than oil, which is fine by me.

If that filter has no oil on it are you sure thats right as you described. On my SS the I have to drain mine the first 1k miles. You can see the oil and air come thru the filter if you do WOT. Have someone do some high revs and look at the filter to see the direction. You should have some oil on that filter if its putting it in the intake.

New2Import wrote:If that filter has no oil on it are you sure thats right as you described. On my SS the I have to drain mine the first 1k miles. You can see the oil and air come thru the filter if you do WOT. Have someone do some high revs and look at the filter to see the direction. You should have some oil on that filter if its putting it in the intake.

Trust me - it's mechanically sound and installed the correct way. The catch can is off to the side of the engine by the washer fluid resevior - that is what will collect the oil.

The clear filter that you can clearly see on the drivers side of the engine is on the low pressure side of the intake and normally would flow into the crankcase 99% of the time. I honestly didn't "need" to put it there, but it is a barrier for any time there is flow reversion in the system to cause crankcase gasses to flow that way. I don't expect that filter to ever have to be changed because 99% of the time the gasses would be flowing into the crankcase rather than into the intake track.

Here's the image of operation for our car.

That is a great writeup. I like the pictures inside the plenum, many people have no clue what it looks like in there.

The first time you replace the plugs is always the hardest. Now that I think about it the only model that is more of a pita is an older Q. I personally find that a combination of extensions and flex adapters allow you to remove the #5 and 6 plugs. The only thing that is harder than the plugs is checking compression.

Very interesting use of things you ad lying around. I am very curious to see your clear filter looks like after a while. Since there is very little oil in the plenum I don't think you will have an issue.

Thanks for sharing.

I checked it last night - put about 1k mi on the car since the install - dry as a bone on the clear filter.

I'm expecting a little oil in there every oil change

Need info.my car felt stronger with new plugs.what does catch can do? thanks,caug

[QUOTE=ken in az]I also needed to perform the Accelerator closed position learning procedure, the throttle plate closed position learning procedure, and the Idle Air Volume learning procedure when all was complete. After that the idle dropped right to 650rpm and ignition timing was near dead on!

I was looking into changing out my plugs since i have been getting worse MPG's and found that you wrote this a while back. How do you do these steps you mentioned?

Just as a quick add , dont spray carb cleaner directly into the open throttle body. If you use a rag or tooth brush , spray that and then clean it

Great pictures!

Did I understand correctly that you changed your plugs at 52k miles. I thought the iridium plugs were good for over a 100K miles.

Excellent write up from Ken.

Just a reminder to everyone - Infiniti DOES NOT RECOMMEND cleaning of the throttle body, especially those with drive-by-wire configuration (e.g. VK engine). There is an anti-gunk coating already on the throttle valve plate and the throttle actuator/sensor is very sensitive.

The first time I cleaned the air intake (MAF sensor, TB, etc.) in my 03Q, I was successful with it. I took all the necessary precautions during cleaning. However, the 2nd time, Aug09, was not successful. It failed the IAVL (Idle Air Volume Learning) which requires 650+/-50RPM at Idle no-load condition. The lowest speed I can get was @ 750RPM, which triggered DTC P0507 (Idle Speed Control) fault code. Beshoff Infiniti-San Jose eventually replaced the TB and reprogrammed the ECM for free, under the Powertrain warranty.

So think twice before cleaning the TB, especially if you are already out of warranty as it can be expensive to replace.