wastegate testing

[wrcruz]

I just want to know the proper way to test the waste gate. Do I have to apply vacuum or pressure to it? I don’t think my is working at all, and I can’t even control boost any more. So am thinking it went bad. Any help will be appreciated.

1993 Laser RS Turbo, 2.5” upper and lower intercooler pipes, all free mods, test pipe, A/F, oil, fuel and boost gauges.

 

[Newlogics]

You can connect air compressor to the acutator, and see when (and if) it starts moving the shutter. That will tell you if the actuator is working. (Make sure to disconnect the compressor as soon as actuator fully opens, so you don't damage it.) It's best to use tire-inflating compressor, because it's slow enough for you to avoid damamge.

If actuator checks out ok, you'd have to take your O2 housing off and see how your Turbo exhaust housin looks arund the waistgate flapper. Small cracks are normal, but major ones will prevent any pressure to be built, therefore not letting your turbo spin as fast as it should spin.

 

[wrcruz]

My turbo spools up very fast, I don't have aproblem with that, is just that I can't control the boost. I have the hallman MBC. Am going to try that, thanks for the tip

 

[Newlogics]

Originally posted by wrcruz
My turbo spools up very fast, I don't have aproblem with that, is just that I can't control the boost. I have the hallman MBC. Am going to try that, thanks for the tip

Where exactly did you loose control of the boost :

a) The MBC won't limit the boost or
b) The MBC won't increase the boost

 

[wrcruz]

Boost just go up to 10, with no control over increasing or decreasing it.

 

[Newlogics]

Originally posted by wrcruz
Boost just go up to 10, with no control over increasing or decreasing it.

Your waistgate is in full operation. Waistgate actuator is factory-set to open waistgate at 10psi.

I would look at your MBC and then your vacuum hoses.
Looks like pressure is consistent before and after MBC, meaning that MBC isn't functional.

Make sure it's connected the following way:

The bottom lead on MBC should go to the any tap in the intake manifold or to the vacuum line going to the bypass valve.
Side lead should go to the waistgate actuator.

What MBC are you using ?

 

[wrcruz]

The hallman Es from www.machv.com

 

[wrcruz]

That's the way I have it set up.
I T the BOV to connect the MBC lower part, and the side to the waistgate. But I have it fully open and still get 10psi when it fact be at its lowest setting.

 

[Newlogics]

Originally posted by wrcruz
That's the way I have it set up.
I T the BOV to connect the MBC lower part, and the side to the waistgate. But I have it fully open and still get 10psi when it fact be at its lowest setting.

10psi is exactly what you should get when MBC is completely screwed out. (You let air virtually pass through MBC and waistgate actuator is limiting your boost.

Did you try to screw the MBC in all the way ? (I assume you do know that you increase boost by screwing the MBC in)