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car will often not boost 2nd turbo. and makes a cooing sound (weird)
It will boost 2nd turbo under following conditions:
1. if past 4500 rpm and you boost a little, then let go of gas and quickly floor it again then all is fine
2. if past 4500 rpm and you are not gassing it, but then just stab the gas.
Other than that all you hear is whinning sound from 1st turbo (12psi) then past 4500 it drops down to like 7psi. then if you let off gas it makes a high pitched "cooing" sound that that drops down to nothing. sort of like "HOOOooooo...."
vacuum tanks and pressure tanks are ok. Any suggestions besides TEARING DOWN THE WHOLE SEQUENTIAL SYSTEM AND DOING IT AGAIN!!!!
I have different boost patterns from you but I hear the same noise. At first I thought it was the factory BOV, then I vented those to the atmosphere and can still hear this noise. It kind of sounds like a video game sound effect or something, WOOOOooooooo. I know wexactly what you mean. Dot know what the hell it is. It only happens when my car struggles to make boost too. Only thing I cn think of off hand is something with a bad vacuum, or air pump. I dont know though. WOrking on the car today.....
dim - check the vaccum hoses under your Upper Intake Manifold. You don't have to remove it to see in there, just unbolt the vaccum/pressure box (which is it, vaccum or pressure, I forget) (black box between your cross over pipe & UIM) and shine a flashlight in under your UIM. I had the same thing you describe and this is what caused it.
Ya, I had never heard dying giraffe (too hard to spell), but I have heard dying goose sounds from the air pump when I had one!
'94 RX-7 Silver Touring
'95 Skyline R33 GT-R V-Spec
'03 Mercedes-Benz C230Kompressor Sport Coupe
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Yeah don't know what the hell a giraffe sounds like in the first place let alone dying, but remember that it's not only the hoses that fail but also the solenoids go pretty easily and there are some people who have seen them fail in different temps. only-really screwy, if you can't figure it out just go non and deal with the lag.
all the clips are ok, but the actuator might be going kaputz since i see a little oil coming out of it. Maybe cuz my turbos are dying too thus leaking oil into the vacuum lines thus going into the actuators thus gunking them up. I'm going to disconnect the pre-control lines and plug them up... Any down side to this?
I have been having a similar problem and I have new turbos. Mine will some times get stuck at 2-3 psi on 1st turbo when I try to get on it quickly (like when trying to race) as long as I hold down the accelerator it just stays at 2-3 psi then as soon as I let off it lets out this high piched pbeeoouu sound like a video game sound effect I did the whole vac job and still have this problem.
Guys have you check your TCA underneth the car it is the big can style actuator and if the c-clip comes undone the you get a strange noise that you are describing... the door sticks closed and prevents any high amount of boost and when you shift or let of you get a funky noise please let me know
You may have a split check valve going to the tca like
Ryan said it sounds like for some reason its not opening.
Unbolt the vacuum tank and look around for any cracked check valves. They will literally split in two and sometimes they look fine but the seal is bad and you can pull them apart so tug on them a little to be sure they are solid. Did you sell your car and get another or just decide to keep it?
if someone shows up to my door with 15k the car is theirs...
All check valves are good. I have a feeling it's the Turbo control solonoid or a split line somewhere. I tied the boost controller to the chamber a of the charge control actuator and this is what I see...
Vaccuum all the way to 4.5k.
After 4.5k it becomes atmospheric
but if i shift gears it stays open
if it's below 4k it stays open
it will only close if i drop the rpm's below 3k
Also when the 2nd boost comes on the first time it makes a intermittent wooshing sound like if a gate is being slapped around... I disconnected the ECU control of the WG and the precontrol and it still happens. My guess is that it is either the vacuum side or the pressure side of the turbo control actuator on bottom. I'm going to hook up my boost gauge on the vacuum tank and see if it's holding vacuum.
Does anyone out there know if the vacuum tank is supposed to loose any of its vacuum during a full turbo run? how about the pressure tank.
I am not sure how much the tanks are suppost to hold but listen to this...
This is a black plastic tank that is buried between the alternator and power steering pump. Kind of difficult to see, removing the Pressure Chamber helps to see it, has one hose connection, and should have a hose attached. This hose comes from the rats nest of metal tubes, and there is a one-way check valve between the rats nest of tubes and the Intake. This one-way check valve can start to leak after a while, causing loss of vacuum to various controls when under boost for a while. A way to troubleshoot this one-way valve leaking is to note a gradual loss of boost and then drop the throttle long enough for your boost gauge to indicate at least 20 inHg of vacuum then slam the throttle back down again. If boost is back up to what it should be then replace this one-way check valve. Basically what this does is "recharge" the vacuum chamber when you let off the gas, allowing actuators to operate properly while the vacuum is still present.
The vacuum one-way check valve goes from the Intake manifold to the Vacuum Chamber via the rats nest of tubes, (Mazda Part# N390-13-995A). This has a layer of three paper like filters on each end for separating any oil from the air.
Try replacing that check valve, if that doesn't work then maybe a bad solenoid somewhere. Also check to see if the check valves are not backwards. That check valve should be letting boost flow from the Ypipe to the pressure tank but not back. Check all the other valves as well, they should flow TOWARDS the UIM.
i did the poor man's sequential and the turbos are fine and they kick in good...
Here is my question... If I wanted to do the turbo simplification...
There is one line that goes from the pressure tank to the LIM. But i don't know if that is correct or not cuz the other side doesn't have a line that leads to a pressure source. Anyone out there do that mod?
I have the same Dimcorner's problem with a strange sound depending on my RPM when I shift into second gear. Sometime i've got no boost and a strange sound.... but if I shift into second gear at low RPM in first , all is ok . With that problem i'm not able to race at a stop....... I can't push hard into first gear!!! :0(
Did you make sure that there really truely are not any dying giraffes under your hood? The pressure from the second turbo may be hurting the poor thing....
Black `94 Touring - The icing on the cake we call the streets
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Originally posted by NoFear99 I have the same Dimcorner's problem with a strange sound depending on my RPM when I shift into second gear. Sometime i've got no boost and a strange sound.... but if I shift into second gear at low RPM in first , all is ok . With that problem i'm not able to race at a stop....... I can't push hard into first gear!!! :0(
Kevin, QC, Canada 94 FD
Check the hose to the BOV, mine needed to be replaced. Once the hose warmed up from the engine heat, it made an aweful sound under boost.