Help, What is the funtion of this thing

[maddog]

Hi All

Ive been useing the search funtion & been reading for hours, but i am getting confused as to what this vacuum or pressure opperated butterfly does.

It is the one post turbo/pre IC.
It seems to get quite oily around it & im wondering if its restricting things.



Most the images of something similar on here are without an IC.
you help is greatly appriciated.

[geeves]

Dont know its function but a few people have removed it with no bad things happening. It might be to do with overboost. The only oil you get round here is from the cranckcase breather and some oil is quite normal (mine will actualy drip from time to time but I have anouther 70000km over yours) If your oil consumption is high fitting a catch can might help.

[maddog]

Thanks geeves, Im not overly worried about it, & im going to put a catch can in the near future, My only issue is blue smoke during cold start warm up.

Otherwise i have no smoke issues at all.
But im thinking about opening this thing up & cleaning it or removing it.
so its good to know other have done the same, just would like to know what its for.

[maddog]

well whatever it is, its normally open anyway. so doesnt have to much restriction.
Its dead easy to remove,& if you want to, very easy to take the butterfly out.

[InVinceble]

Spooky I was just about to ask the same question after spending the last hour "researching" into it.
I reckon it is part of the "Quick Warm Up System". I'll go so far as to put my neck out and suggest it is the FICD - Fas Idle Control Device.
If, and my fingers are crossed on this one, it is then it's function is to control the amount of the intake air, and change the air ratio which is supplied to the cylinder. All this is obviously dependent on the switch on the dash being on and the ambient temperature being below 8 degrees.
Check under your car and see if you have the corresponding exhaust throttle too, although that was more of an optional part.
Bottom line: If you don't use the quick warm up option it should be safe to remove it! Guess what I'm off to do!

[geeves]

Are you sure you dont need the fast warm up device. I was down your way a few months ago and saw -8 for 5 nights in a row.

[geeves]

On a side note in the top pic from maddog you can see a small line from the corner of the intercooler This is the line my boost gauge is T'd into

[InVinceble]

Geeves - in response to your first coment I'll say the same to you as I am frequently told by my "mates" (being as I am from the land of central heating)...... "harden up man!" ;D
In regards to the boost gauge install, why should it make such a difference taking the pressure from either side of the intercooler?

[geeves]

I would much rather a -8 winter in Dunedin than the cool slime that passes for winter in Wellington. I lived in Dunedin for 4 years and Balclutha for anouther 5 a very long time ago Before that I came from not far from your origins.
Since were hijacking this thread Ill take the other reply back to wear it should be

[maddog]

just an update, When i pulled off that inlet with the butterfly in it, I took the oppertunity to take off some related parts of the intake & give them a good clean,as there is a fair bit of blow-by oil in there, So I will certainly need to get a catch can soon.
Removing the inner of the butterfly also didnt seem to make any real differance for those thinking of doing it.
On another note, ive read about how these engine like to only have the oil level halfway between the marks on the dipstick, so I have just finnished draining out about 300ml to bring it down to this level. will leave test drive till tomorow & see if it feels any different. & reduces cold start blue smoke.
Incidently it currently running Titan 15/40, is this a good oil ?

[billyvanboheman]

Couple of educated ideas on what it does.
My Father has a diesel fuel injection business and even he is not 100% on it's main purpose.
According to him it is operated by a sensor on the injector pump that closes the butterfly via the vacuum servo on throttle off.
This stops the engine from sucking air on run down.
The most educated idea on it's purpose is to help aid in stopping engine vibration due to the high compression on run down and stop.
Maddog, on the blue smoke on start up question associated with this, is it oil or unburnt diesel smoke?

[geeves]

Biggest change with the lower oil level is less leakage from the front and rear main seals. On first start a diesel will puff blue for the first min or so Diesel is an oil. Just keep an eye on oil consumption.

[maddog]

My rear main seal was replaced when the clutch was done a month or so ago,so i dont have any oil leaks to speak of.
The smoke suggest its oil, perhaps getting sucked in from from the intake, it isnt that noticable when idling during warm up, but slowly increase's untill you give it arev,then it comes heavier. it stops once 50m down the road. Seems to just need to blow it out of its system. It could posibly be coming from a build up of blow-by oil in the IC. I dont think its been cleaned out in about 50-60k kms. but would unburnt diesel be a light blue colour ?
Just thinking

[billyvanboheman]

Yip unburnt diesel and oil produce the same colour, only way to tell is the smell test (not dodgy) the exhaust blue smoke with the smell test will tell you if it's oil or diesel.
If it is oil smoke it's also worth checking the valve seals or more extremely the valve guides.
Non existent seals or worn guides will cause the smoke you have described.
Another possible cause is timing, if it's retarded slightly it will also cause it.
Also from the previous posts the quick warm up switch operates the exhaust butterfly that InVincable was talking about and he is correct, there is a sensor on them that means it will only work if under 8 Deg.

[maddog]

alright i get my nostrills out in the morning. & try & desribe it.
I really must get my timing reset sometime soon anyway.
Im not overly concered about the smoke, its just a little unsightly.

[billyvanboheman]

I know the feeling re the smoke, mine is black on acceleration/deceleration, fine on constant revs, it's always done it and as you say just unsightly, and bugging!!
That's why I was looking into the EGR removal, turns out it looks like mine has had the pipe from exhaust to inlet vacuum servos removed already.

[James W]

"Yip unburnt diesel and oil produce the same colour'

Unburnt diesel doens't look blue, it is either white (not hot enough) or black (not enough oxygen). Ever seen the nice white smoke trails behind an aircraft in a aviation display? It's diesel injected into the hot exhaust manifold..... It's also a common student trick for the undi 500. Diesel in the windscreen washer bottle and shift the hose into a small hole in the exhaust somewhere.

"mine is black on acceleration/deceleration, fine on constant revs"

It might be a good idea to wind down the fuel flow.... or service the air cleaner.

[mudgrip4]

Hi maddog - you truck pic looks very familiar - did you buy this isuzu from Sacha, a lady from my Canterbury club?

I wouldn't worry too much about the early morning blue puff which lasts for about 50 meters up the road and then disappears. Exactly what mine has been doing for about 100,000ks. And mine doesn't use oil. Just seems to be a bit of oil that condenses in the rocker cover and tubing into the turbo and passes through the turbo with a bit of blue on start up. Is also increased by worn valve guides/seals. Wouldn't worry about it - alot of 4JB1-Ts do this.

Re adjusting your timing, give me a call if you like - have walked down that road and a good increase in performance is easily available

Mike 3224570 Chch.

[maddog]

Hi Mudgrip,
Yes this is Sacha old truck. Nice lady, & very passionate about 4wding. Showed me a video of her nearly tiping it, Where you there ?

I didnt buy those big mud tyres & gold wheels with it, But ive got some more Solid steelies lined up through a workmate.

Ive read your thread from a while back & been even more convinced than ever about performance gains from timing advance's

Is that blackwoods place still in opperation ? If not who do you reccomend in Chch ?

[mudgrip4]

give me a buzz at number above and should be able to sort out tuning for you.

Mike