I cleaned my throttle body 2 weeks ago using the rag/tooth brush method. Actually it was pretty clean, but it did make a difference in the way my car starts and idles. So I got to thinking again. There's a lot of airway passage after the throttle body. The whole intake manifold must also have some gunk on it. How could we get the intake cleaner to get all the way back there?

Here's what I did.

Disconnect the intake at the throttle body and unclip the airbox so the top half can move. Those with pop chargers and other intakes will not have to do that. Leave the MAF sensor plugged in and slide the rubber accordian thing off and slightly to the side leaving a nice sized opening to spray in. This is going to give the engine lots of false air. **IMPORTANT** Do this first thing in the morning with a cold engine so it runs in open loop mode. (runs longer before the stalling happens) Next start your car (remote start helps a lot here) keep it running and spray the cleaner into the intake while giving it gas to keep it running. The cleaner will get sucked into the throttle body and down the intake plenum (sp?) cleaning all the gunk out from deep inside. (lots of nasty exaust comes out too) Be quick and keep revving it. Get as much cleaner ingested as you can. The engine will start to die as it tries to run in closed loop mode so you only get a few min. before it shuts down. You can start it once or twice more but after that it just wount run. I got about a 1/4 of a can in there before it wouldn't run anymore. Then I took a peak in the throttle body, it was indeed nice and clean all the way back in there. It took lots of grim away from the intake plenum (sp?). Put everything back together and take it for a spin. I got no MIL light which was suprising. I thought for sure I'd throw a MAF sensor waring. Probably would if I kept on starting it after it stalled. I'm still runnig very smooth and nice and strong with my little getto air box mod. Now that the entire intake system is clean I can rest at night!

 

anything noticable? what is closed loop mode?

 

Yes, a very clean intake system. A clean intake system lets air flow smoothly.
Closed loop mode is when the ECU runs on a preset air/fuel mixture. It's not relying on the sensors to make adjustments to air/fuel/ignition ect... It only runs in this mode when starting up cold. After your car warms up it runs in open loop gathering information from your sensors and making adjustments to fuel/timing ect... Thats when it becomes important not to let any false air into the intake (after MAF sensor) or your car will not run correctly. In this case it stalls.

 

Won't there be after-effects from puting a cleaner thru your engine? What kind of goo is being left in your cylindars and on your valves? I doubt any cleaner is clean burning. What cleaner did you use?

I'm curious....I would love to do this if it's truly safe.

 

I just took the TB and intake manifold off. My 3-gen VE runners were not that bad.

Another way is to feed small amounts of water though a vacuum port while high idling the car. Probably safer than running cleaner though(though that's what alot of people do here)

 

What cleaner should I use?

 

hey tom,
Do you think you can help me clean mine too?
Like you helped my with me AGX's?

JOHN

 

i think the water method broke peoples stuff... thats kinda vague but i know it had problems and was generally thought to be a bad idea

 

COrrect me if im worng, but wouldnt water make the engine seize?

 

After I cleaned my throttle body my idle started jumping. I used BG 44K fuel additive and the idle is back to normal. I thought I'd post this incase it was happening to you.

 

All you do is remove the intake up to the TB(throttle body) and then spray insideby moving the butterfly slightly while car is on. Turn it off spray and clean. Put the intake back on and start the car. Repeat few times. Make sure not to spray into TB more then 30 sec each spray or you will burn your cat. Never sparay though the intake you will damage your MAF. Its very helpfull to clean your TB. Good Luck.

 

1) I used GUNK Air Intake Cleaner

Directions on the car read:

A) Start engine, place cloth to absorb any excess product bla bla bla.. Spray cleaner into throttle body while manually working butterfly valve. Spray approx one min. or 1/2 can. Replace intake hose and run engine.

B) Do not start engine. Place cloth..... bla bla bla. Srpay cleaner into butterfly and wipe with cloth. Start engine.

So the cleaner doesn't harm the engine. Just like good old carb cleaner, it gets burnt up with the rest of the junk. This method just gets the whole intake nice and clean. A good wiping of the butterfly area after that is a good idea as well. I did part B on Saturday, (butterfly area) then (cold engine) Sunday morning did part A. Now I know my entire intake path is clean.


JOHN - I'd be happy to show you how this is done. Only thing is we really need a cold engine in order for it to run for a few minuts with the intake hose disconnected. Drop me e-mail and we'll set up a day. I'll do the butterfly area (part B) and show you how to do "part A" yourself in the morning.

 

My car never stalled with intake open.

 

Ummmm..... I think it is like this:

Open Loop:
-running with out any feedback from the O2 sensors.
The O2 sensors are not used to determine the fuel mixture until the O2 sensors are at operating temperature. The ECU runs from pre-programmed values.


Closed Loop:
-running with the feedback of the O2 sensors. The ECU uses the input from the FULLY WARMED UP O2 sensor.

The term "closed" is to indicate some output feeds some input, like a loop or circle.

 

No, you have it backwards. Read MaxVQ's post for correct info.

 

I don't want to argue this point. Perhaps we should have somebody with a FSM look this term up as Nissan sees it. Electrically a closed loop has no input. It's fixed, like a circle. There are no variables.

An open loop can gather input and make changes to the output. It's continuously variable. It has no fixed or preset conditions and constantly changes.

Now Nissan may term things differently, but controllers (our ECUs?) work on open and closed loop modes. Closed loop mode runs preset variables. In open loop mode, output depends on input.


BUT, maybe I do have all this backwards, but you get the piont.

 

I've used a product called "Seafoam" before, however I have not tried it on my MAX. You suck as much of this stuff into the intake manifold through a vacuum tube and it will stall the engine out. After a few minutes you start the car up and all of the deposits get burned out. It's much safer than water since it is a petroleum distillate.

 

nj,
open loop and close loop is a term penned in not just cars but other electronics. In open loop, stored values are used (in vehicles, these are the ones programmed into the EPROM). In close loop, the information from the sensors are used to determing fuel supply, timing, etc.

 

So I did have it backwards! You learn something new every day. I'm going to go back and edit my original post.

 

does any one have PICTURES of this? I really don't feel like paying the dealership to do it...but I want pictures.

 

I was wondering how often this should be done...

This morning I was at my dealership to get some rear brake pads and the counter guy suggested that I should have my throttle body cleaned. I'm at just under 70,000 kms and I don't want them to touch my SC intake setup.

 

Well...I did it. After contemplating then realizing the impossibilities in a Q45 TB upgrade, I decided to buy a can of GUNK. That sh*t is sick!!! It was really easy. I was reading that because you remove the intake in order to access the TB that the MSF will stall out the car due to false air. To fix this, instead of removing the intake, I just took it off the TB and moved it slightly down, still enabling the intake to do its job....then I sprayed a can of GUNK in the TB while reving the engine with the TB's cruise control rocker. It worked great! The I did Iansw's Max.....both cars are now squeeky clean....

Then I had Iansw reset my ECU...just to be safe.

I tested the cleaning performance with a Butt-Dyno, but there was no noticable difference. The thing I can notice is a quiter, smoother idle....which is nice....geez...with this cleaning, synthetic oil and new NGK plugs....I an barely hear my engine when it's idle...