By pass valve not opening

[Chrispy0530]

So I'm really stumped at the moment.

Was driving the car yesterday, went on a on-ramp and built about 13 PSI, and noticed compressor surge instead of the by pass opening up. When I got to my destination, I saw that the vacuum line had pretty much cooked itself as it was a bit too close to the exhaust manifold.

No problem. I go today to buy several ft of vacuum lines. The line that broke was from a External Waste Gate, to a T, which connects to the BoV, and the Intake Manifold. Replaced the broken one and it still surged one me, which I thought was weird. So I replaced it again with a smaller hose, same thing. Went ahead and replaced all 3 lines that was connected to the T, and replaced the T itself and same problem.

Vacuum is set at 22 at idle, no boost leaks, and the BoV is only 3-4 months old, so it would be odd for a diaphram to just fail that soon.

..Really don't get what's going on here.


By Pass Valve = NGR Type S
Eternal Waste Gate = Tial 38

No boost controller.

Everything was fine before that line melted up.


Edit: BoV works perfect on a friends car


Don't know what else to do here

 

[dsmdeliveryboy]

So I'm really stumped at the moment.

Was driving the car yesterday, went on a on-ramp and built about 13 PSI, and noticed compressor surge instead of the by pass opening up. When I got to my destination, I saw that the vacuum line had pretty much cooked itself as it was a bit too close to the exhaust manifold.

No problem. I go today to buy several ft of vacuum lines. The line that broke was from a External Waste Gate, to a T, which connects to the BoV, and the Intake Manifold. Replaced the broken one and it still surged one me, which I thought was weird. So I replaced it again with a smaller hose, same thing. Went ahead and replaced all 3 lines that was connected to the T, and replaced the T itself and same problem.

Vacuum is set at 22 at idle, no boost leaks, and the BoV is only 3-4 months old, so it would be odd for a diaphram to just fail that soon.

..Really don't get what's going on here.


By Pass Valve = NGR Type S
Eternal Waste Gate = Tial 38

No boost controller.

Everything was fine before that line melted up.


Edit: BoV works perfect on a friends car


Don't know what else to do here

Its because your t'ed off the bov vacuum line, you need to be running the vacuum line from a pressure source such as the J pipe and from there it needs to go to a mbc and then to the wastegate.

 

[Chrispy0530]

The actual source, is coming from the intake manifold (Evo 3, have it coming from the main nipple pointing towards the injectors), and instead of going to the BoV directly, it's T-ed off and splits to the BoV, and the External Waste Gate.

I've had it running like that for as long as I can remember and had no problems with the BoV opening up.

Unfortunately, my J-pipe doesn't have any kind of nipple on it at all.

 

[Chrispy0530]

Still stumped on this. Running out of idea's here, and running under straight vacuum is a lot harder then I thought.

 

[Chrispy0530]

Last plea for help here.

So I did get the BoV to open up again. Turns out the plastic tee had little holes in it causing leaks. But now I've had a problem with my External waste gate not opening up. That, and the car hardly builds any boost when under load. Will get up to 5PSI at around 3.5k RPM (supposed to be 15PSI) and the waste gate will not open up.

 

[dsmike1]

Sounds like the wastegate is stuck open, or the mbc is set too low. What psi spring do you have in the wastegate?

 

[Chrispy0530]

There is no MBC on. Spring is a 15PSI.

 

[LiquidX]

I though you said you didn't have any boost leaks and then you find one in your plastic tee?? Redo your test, pressurize it to 25psi and use a spray bottle of soapy water and look for bubbles.

What gear are you getting your numbers from and do you have any pre turbine exhaust leaks (cracked manifold, leaking gaskets, etc)?

 

[pbwu1f]

I would tap into the j-pipe and plug the WG into that. Then the BOV will have its own hose. IF that doesn't work then something is wrong with the BOV. Also try turning the adjustment screw so there is less tension on it and see if it opens.

 

[Chrispy0530]

I though you said you didn't have any boost leaks and then you find one in your plastic tee?? Redo your test, pressurize it to 25psi and use a spray bottle of soapy water and look for bubbles.

What gear are you getting your numbers from and do you have any pre turbine exhaust leaks (cracked manifold, leaking gaskets, etc)?

Think I might've done the tests wrong. I'll go ahead and redo it when I get a hold of another tester.

I would tap into the j-pipe and plug the WG into that. Then the BOV will have its own hose. IF that doesn't work then something is wrong with the BOV. Also try turning the adjustment screw so there is less tension on it and see if it opens.

The J-pipe has no nipple or anything to attach the hose to. I might just try and hook it up to another vacuum port on the manifold.

 

[dsmdeliveryboy]

Think I might've done the tests wrong. I'll go ahead and redo it when I get a hold of another tester.




The J-pipe has no nipple or anything to attach the hose to. I might just try and hook it up to another vacuum port on the manifold.

That is why you buy a fitting(depending on what the J pipe is made out of)and have it welded to your J pipe, I PROMISE you that will fix your problems.

In my case my J pipe is aluminum and is not able to be drilled and tapped, so I bought a AN fitting and drilled a hole in my J pipe and got the threaded fitting on the left welded on(these are aluminum)then just threaded on the vacuum fitting on the right(pressure rated up to 300psi).

You must be logged in to view this image or video.

 

[pwner]

Think I might've done the tests wrong. I'll go ahead and redo it when I get a hold of another tester.




The J-pipe has no nipple or anything to attach the hose to. I might just try and hook it up to another vacuum port on the manifold.

IIRC, isn't the wastegate vacuum line supposed to be pre throttle body, and the
BOV is supposed to be post throttle body?

We had this same problem w/ a buddies car and just switching them around fixed it. We had to drill and tap a hole in the J pipe though because his didn't have a nipple either.

 

[Chrispy0530]

But the EWG worked perfectly with the setup before though. Why would it suddenly not work not?

 

[LiquidX]

Pressure test to 25 psi or higher depending on what pressure you will run. Spray everything that sees air, both positive and negative, with soapy water and look for bubbles. That is really the only for sure way to find a leak.

Not all leaks make noise and not all leaks will allow enough outside gasses in to make a difference in idle speed unless it is localized on the leak.