Boost not holding

[Corleone]

Recently purchased a stainless steel manifold in the hope of reaching a bar of boost. (fuelling already taken care of btw )

Got the car all back together and raised the boost via bleed valve and now instead of the boost creeping up as it did before. It now creeps down :S

Am I right in guessing this is something to do with the actuator?

 

[GT-TD04]

did you check for a leak?
is the bleed valve fitted right?
was the actuator touched?

 

[Corleone]

am i right in putting the bleed valve on the vacuum line that comes off the top of the actuator? Or should I have put it on the same line as the Hi/Lo solonoid, but I couldnt really see how that would work?

No leaks from what I could see and the actuator has not been altered other than the bleed valve.

Considering a new actuator soon but just wanted to test the bleed valve as I couldnt wait to get the boost up :drive:

 

[GT-TD04]

http://www.toyotagtturbo.com/forums/showthread.php?t=20649

Like above?

Are you sure you turned it up instead of down? whats its maximum boost atm?

 

[Corleone]

Before I was getting 0.7 creeping to 0.8 by bypassing the hi/lo option.

But then with the valve i was getting 0.8 then dropping to 0.6.

I have an inline type installed like that but it doesnt have a direction marked on it.

Similar to this

 

[GT-TD04]

3 nipples?

Try swapping the pipes,still reckon theres a leak somewhere,all the pipes to the turbo are back on yes?including intercooler ones?

Is the mani attached to the turbo alright?

 

[Corleone]

No sign of blowing. Everything from the turbo outlet to the inlet manifold is tight and unrestricted. I will double check for any leaks tommorow.

But yeah the third nipple is for bleed air into atmosphere. Although, am I aiming to restrict this rather than let it bleed to atmosphere?

 

[Corleone]

Just tried disconnecting the actuator completely and still it wont reach a bar without dropping :S

Wastegate/Actuator related?

 

[WallaceGlanza]

Just tried disconnecting the actuator completely and still it wont reach a bar without dropping :S

Wastegate/Actuator related?

Disconnecting the actuator completely? If you did this you wouldn't get any boost!?

If you mean you've disconnected the mbc and just running off the actuator then it definately sounds like a weak actuator to me, the stock one's are known for this. An HKS actuator will solve it.

 

[Corleone]

I thought that the actuator is opened from the force of the boost pressure working against the spring. Hence why it boosts high when i have disconnected it. Or am I wrong?

Ive had my feelings its the actuator, but just wanted some confirmation really.

How are Toy Tuning actuators compared to HKS?

 

[Nwimie]

nooooo the actuator holds the waste gate shut there for creating boost. if you have disconnected the actuator your waste gate would be permantly open there for not creating any boost atal.

 

[Corleone]

Well i would disagree as im getting plenty of boost with the actuator having no pipes attached.

I thought it was the spring that holds the the wastegate closed. Then boost pressure opposes this to open up the wastegate?

 

[Nwimie]

disconnecting the VACUUM pipes is different to disconnecting the actuator matey. so slight miss understanding there.

 

[WallaceGlanza]

If you've disconnected the vaccuum pipes and the boost drops then its definately the actuator, it should make infinite boost as the wastegate wouldn't open, so the spring must be weak.

 

[Corleone]

Ahh i seee! I was starting to question myself there!?!

Thanks for the help. Im now pretty sure my actuator must be in need of replacement.

 

[Phil]

also to note if its a ct9 no matter what boost you get it to peak at it'll drop off in higher rpm.

Phil

 

[rmsnoel]

How do you port the wastegate?