WHAT'S THIS and WHY

[makeitfit]

Got to get some air time mate as I'm closer to the ground than you:augie

 

[clivvy]

i have similar issues, nothing major though. I am going to look at ti this Saturday, but what are we saying, remove that funny disc shaped thingy form the intercooler?? how do I disable it, i am confued as to why its there, but diabling it makes everything work better!!

sorry, i am fairly new to this, but eager to know more!

 

[makeitfit]

Ay , dissabling it worked for me and my mate with exactly the same engine
We just took the vacuum hose off and stuck it on the clutch bleed nipple
Works a treat:thumbs

 

[guncharmer]

i have the same throttle control valve set up,the workshop manual says you should be able to see the plunger at the bottom move up and down ,which opens or closes the flap or anywhere in between, in response to increase in revs. this is controlled by the vacuum supplied to it which itself is controlled by solenoids found on the nearside inner wing.the ecu controls the amount of vacuum by pulsing the solenoids open or closed and forwarding the vacuum from the vacuum pump via the pipe to the valve.the egr valve works the same but i am not sure if its variable and think its either open or closed.

the valve on mine is always open(its at rest vertical) as i had the intercooler off and looked. if i connect the vacuum pipe from the vacuum pump direct to the valve the plunger goes up and the flap closes across the intake airway(its not airtight or anything,just restricts flow). so my solenoids dont do what they are supposed to but they are not faulty,i have to assume that the ecu isnt telling them what to do.
i have the engine light on permanently with a fault code po235 which tells me i have a turbo boost sensor circuit A malfunction. i have not got a turbo boost sensor. i have given up trying to work out whats wrong.it drives ok apart (sometimes) from a stutter in first or second with a bit of white smoke which i think is ecu related. i have posted on here about this fault code before to no avail but i did once come across a link to a web page that was suggesting the bosch ecu was prone to throwing up this fault code,thats when i gave up and settled for what i have got because even though it is slowly driving me insane i cannot see a cheap or even reasonable price to fix, i nearly bought an ecu secondhand but found out they have to be programmed to the car by nissan.i am on this forum most nights hoping the solution may pop up.
finally i was going to block the egr valve as it may be stuck in the wrong position but it is so bloody inaccessible the last time i set about it i lost the will to live!

 

[makeitfit]

I was late for work today so didnt get a chance to dissarm it.
EGR that is
Hope to get time tomorrow.
I know what its like banging away looking for the answer:augie
Took my whole dashboard apart to find the ECU and then it was ok anyway:banghead

 

[extreme-4x4]

are your hoses crossed... maybe its not opening what should be.

they are color coded at the airbox end

maybe pete could tell you what color hose goes where
or we could do it together on wednesday and do some pics

it might help you:nenau

 

[extreme-4x4]

I was late for work today so didnt get a chance to dissarm it.
EGR that is
Hope to get time tomorrow.
I know what its like banging away looking for the answer:augie
Took my whole dashboard apart to find the ECU and then it was ok anyway:banghead

yeah and who fixed it .......... eventually

 

[makeitfit]

You the man on the hose front:thumbs

 

[guncharmer]

to makeitfit, the fact that your valve opens when you pull off the pipe suggest you have vacuum going to it all the time. the fault might lie with one of the solenoids. i am guessing you will have three of them same as mine and the pipe fitments on them should be colour coded. the solenoids are all the same so you could try swopping them about to see if your throttle valve becomes operational.
make a drawing or take a photo before you start swopping about as even with the colour coding it can get confusing as to which is pipe in or out. there is a way of testing them which is to do with applying voltage and you can here them click which is opening or shutting to let the vacuum through or not.cant remember right now but its in the workshop manual.

 

[extreme-4x4]

makitfits one , before we pulled the pipe off

the air flow was closed on tick over until say 2500 rpm then it opened the airway. but if he took his foot off the gas the airway closed immediately and forcing it to drop the rpm and wouldn't open until 2500 rpm . this was causing the turbo lag. it just wouldn't let the air in

without the hose to this. the airway is fully open all the time
and he has proper pick up

 

[guncharmer]

So its an all or nothing situation with the flap,something is trying to work,i think 2 of the solenoids control the flap ,one of which pulses rapidly to get the variation. this forum desperately needs a nissan technician on it otherwise its all guessing and trial and error.of course if expense was no object no probs,down the nissan dealer,replace every sensor,solenoid,turbo,ecu,throttle pedal assembly,14hrs labour etc. check continuity!,might as well build another one.

 

[extreme-4x4]

well all the other tdi's dont have it, so its fully open anyway,

it seems its just the really early ones when they changed from td to tdi
it could be they found its better just to leave it open. i don't know im not qualified.

but it works on his, and he's done it to his mates one too

i doubt a Nissan technician would know any better. the days of a proper mechanic are gone they don't mend things anymore. if the computer says its not working they replace the part... they are just fitters now

that's why you have forums to fix things (at your own risk of course)

my grandad was a mechanic and if it broke he made another one or made it work:bow

 

[guncharmer]

when i say a nissan technician i mean someone who actually understands what each part does and why and there must be a few out there. thats why i have not been to a nissan dealer because there is no guarantee that anyone in the workshop has got themself clued up. an eighteen year old reading a flowchart could rack me a bill up of £500 easily without getting near the true problem.

mine is an 01 with a throttle control valve and the 03 plate i was looking at on ebay has one too.(both commercials).

 

[extreme-4x4]

that will be toolbox then. he's about the closest we have. as far as i know :bow:bow:bow:bow

 

[extreme-4x4]

update..... seen a few more with these on now??????

why is it some do have it and some dont

it seems to be not nissan and ford specific either some fords have it some nissans have it too...... so why some and not the others ?????????

 

[wildbri]

I have just nipped out to look at my t2 and I have one......nice shiny brass thing with a rubber tube coming out of it.... bri

 

[Adz]

Have we found out what this actually does.?

Mine ran like poo & lost power when removed.!

Could someone else try it & see if it does the same to theres.?

Its baffeled me too.?

Its seems to be an actuator type thing.?

:surrender

 

[lacroupade]

Just to add to the confusion, wife's 99-plate round headlight truck hasn't got one, but my 02-plate does! Obviously can't see what its doing when underway, but the plunger is out on startup but pops in after about a minute and stays there. No engine probs I am aware of...:nenau

 

[extreme-4x4]

i suspect ... with pete's one the hoses are crossed elsewhere or the actuator is faulty. hence his problem.... but its fixed now i recon just removing the hose

 

[lacroupade]

i suspect ... with pete's one the hoses are crossed elsewhere or the actuator is faulty. hence his problem.... but its fixed now i recon just removing the hose

so how come mine just pops in after 30 secs and stays there, I might look at disconnecting it somehow....it would seem anyway that I have EGR after all..?

But check out this....