where has my boost gone??????

[jellis]

hey guys and girls. i have no idea what has happened my mechanic cant work it out he has had a look at the turbo and its in good condition. there is a bit of oil in the intake pipes but my mechanic tells me that this is noraml so he and i are both stumped as to what is wrong with it he has looked at all the fuel lines and the the diaghram thingy he said all were in good condition. there are no strange noises coming from the engine bay. but there is just no boost. this car is seriously starting to frustrate me as i havent had it driveable for 4 weeks now due to several problems. does any one have any idea as to what it could be.
cheers josh,

[jezza]

waste gate seized open?

[pig75]

check the overboost and egr valves

[geeves]

How do you know No boost?
If its just a gauge reading then suspect the guage or hose going to it. (been there done that) If its running ok but the guage says 0 it will be this
If not see below
Other possibilities
Cold start device jammed on This is the flap thing in the exhaust just below the turbo on the 4jb1
Wastegate jammed open as already suggested but also the waste gate connects to a butterfly in the inlet to control boost. This can also jam closed.
Damaged or restricted exhaust or inlet ie air filter
how did you check the turbo was ok?
A blocked oil line to the turbo would also cause this but also other damage

[jellis]

waste gate seized open?
how would i check this?

check the overboost and egr valves
where is the over boost valve not sure how to check egr valves?

How do you know No boost?
If its just a gauge reading then suspect the guage or hose going to it. (been there done that) If its running ok but the guage says 0 it will be this
If not see below
Other possibilities
Cold start device jammed on This is the flap thing in the exhaust just below the turbo on the 4jb1
Wastegate jammed open as already suggested but also the waste gate connects to a butterfly in the inlet to control boost. This can also jam closed.
Damaged or restricted exhaust or inlet ie air filter
how did you check the turbo was ok?
A blocked oil line to the turbo would also cause this but also other damage
geeves

na no boost gauge just dosent feel the same feels like there is no power from 2100 up.
would the cold start device affect the motor during the lower revs aswell or just the higher ones?
to check if the turbo was ok i took all the intake plumbing off it and played with the blades to see if there was any free play forwards or back or up and down seemed nice and stiff but still spun fairly freely, fins all looked to be intact. thats just how i checked it not sure how the mechanic did

cheers guys so glad there is a group of people out there that know what there talking about as im bloody hopeless
josh,

[Demonic]

na no boost gauge just dosent feel the same feels like there is no power from 2100 up

I find that on a straight i get almost no boost, only when the vehicle is underload (like going up a good hill) that i really notice the boost.

[geeves]

My money is on something affecting gas flow.
Its hard to test the wastegate but there is a lever on the side of it the conects to the butterfly. Figure out sme way of seeing if it moves and take it for a drive. I would tie a single long wifes hair to it and see if it breaks when driven but you might find a more practicle way.
Also Check the cold start device in the exhaust. These do seize and always seize on. Theres is some info somewhere on the old forum.
good luck

[pig75]

When was the last time you changed your air and fuel filters?
This is the overboost valve

over0.jpg

[jellis]

When was the last time you changed your air and fuel filters?
This is the overboost valve

over0.jpg

fuel and oil filters less than 500kms ago air filter 10,000kms ago

My money is on something affecting gas flow.
Its hard to test the wastegate but there is a lever on the side of it the conects to the butterfly. Figure out sme way of seeing if it moves and take it for a drive. I would tie a single long wifes hair to it and see if it breaks when driven but you might find a more practicle way.
Also Check the cold start device in the exhaust. These do seize and always seize on. Theres is some info somewhere on the old forum.
good luck

ok will have a look tomorrow its still at the mechanics today so if he cant find out what it is i will be taking it back to sydeny with me will be a slow trip if its not making boost lol

[geeves]

How far do you have to go? Keep an eye on the temp because it might overfuel without boost