wastegate actuator.

[scott_83]

My turbo actuator is releasing the pressure giving me over boost.
I have taken it off to check that the wastegate is actually moving and it is very free.
ive tried the actuator on a vacuum and nothing happened. But yet it moved when I pulled the rod.

I always thought they operated on a vacuum?

Can anyone help on this and how I can test it.

cheers

 

[RsvRob]

Actuator works on pressure not vacuum...
Are you saying it's leaking and causing over boost because it's not opening the wastegate...
What model?
Is it actuator with the hat on?

Can try blowing in it, if you can with no resistance then the diaphragm is split

 

[scott_83]

Whats its doing is the boost pressure is getting so high so i think the ecu is cutting the fuel and giving me wipelash.
Its a 5.
Its got a forge on with a red spring on. It was fitted before I bought it in november so hasn't been on there long.
just blown down it, there is definatly pressure there.

 

[RsvRob]

Possible fuel cut.
Full throttle it boosts high then feels like you hit a wall and the engine cuts!!
Spring may have failed. Has it always happened or only recent.

 

[scott_83]

Well the actuator pipe got cut by the fan cowling so ive changed that. then It had a missfire so I fixed that.Also the recirc valve broke so I replaced that then it would do it every now and then now all the time when I boost.

The pipe I used to replace the actuator pipe is thick walled but isnt vacuum pipe would that make a difference?

 

[RsvRob]

Unless you have another leak I'd suggest the actuator is knackered. How is your boost controlled?

 

[scott_83]

Just a normal 2 port valve.

 

[scott_83]

Is it possible I have put the pipes on the wrong way round to the 2 port valve

 

[RsvRob]

Ok
So you now have 2 options...
Solenoid has failed or
Forge actuator has.
What is the red spring rated too?
Try connecting the actuator direct to j pipe and see if you over boost

 

[RsvRob]

You never said the solenoid pipes had been removed lol

 

[scott_83]

20 psi.
J pipe?

 

[RsvRob]

J pipe.... From the turbo

 

[scott_83]

I remember checking pipes for leaks .
there is 2 pipes off to valve. One that goes to actuator and the other goes to the air intake I think

 

[scott_83]

Is that so it runs off the boost pressure?

 

[RsvRob]

J pipe will build boost and pass directly to the actuator. This will then activate and open the wastegate to release pressure. This is determined by what the actuator is set at. You say 20psi. If you do this then you have eliminated all other parts from the equation and can see if it's the actuator. If it work's fine then I would suggest it's you solenoid

 

[scott_83]

Ok will try that tomorrow.
Just to check I have got them on the right way round. On the two port which way way do the pipes go?

 

[RsvRob]

No idea. I only ever run j pipe to actuator or a 3 port boost control lol

 

[scott_83]

Ok thanks very much for your help. Will post back on here tomorrow

 

[scott_83]

Hi rsv rob. Only just managed to get back on my evo in the last week. I have removed the actuator and tested it. Works ok. Refitted it and run the pipe straight to it from the turbo. Works ok. I have then run new pipes to to turbo and actuator from solenoid and blown down it with an air line. Works fine. Im concerned about my solenoid. I pressure tested it and it slowly lost pressure. Is this common? What also concerns me is that I checked the voltage feed to the solenoid and its at 14v almost permanently on idle. I thought its only ment to be live like that at full boost? Is the map sensor controlling this?

Cheers

 

[RsvRob]

Unsure of the voltage but I believe it doesn't activate until a certain load. So on idle there is no load.
If boost works fine on actuator then it is the solenoid. Just replace it with a 3 port and map it in.
Stop thinking of other more complicated problems causing it. It's normally more simple than you think.