Boost Control Issues???

[vince_w2004]

I have researched this question for about 2 days now, and have only fixed half my problems. Please excuse me if i am asking a common Q&A.
I purchased a 1994 GST TDO5 big 16g bored .20 head work, front mount, greddy bov.
The car came with a manual boost controller that didn't work at all. The car will run 15psi with it hooked up but i keep blowing off my inter cooler clamps. I was trying to solve this problem by fixing the boost controller so i could run around on 10 psi. The boost control was running off a 3 prong vacuum connector coming from the intake manifold which also supplied to the bov. I also found that my waste gate actuator is not moving at all when the boost is adjusted. Well after much research on how to install a manual boost control, i found a that the proper way to install the boost controller and went from there. I ran 1 hose off the j pipe to the controller and 1 hose of the controller to the waste gate. And i ran 1 hose from the intake to the bov. Still no control over boost. So i took the hose from the j pipe and ran it straight to the wastegate. Now the car runs good but the turbo docent spool as fast and it tends to creep up at higher rpm's instead of just climbing steady. Also the bov docent seem as loud at low rpm's either.

Now what I am wondering is if the waste gate actuator might not be working properly or is there not enough vacuum to let it work properly. Or am i simply not running the right line to the right parts. I have checked all the lines for damage and have checked boost controller to see if it allows air to flow. It seemed fine. Any recommendations would be greatly appreciated.

 

[kenamond]

I have researched this question for about 2 days now, and have only fixed half my problems. Please excuse me if i am asking a common Q&A.
I purchased a 1994 GST TDO5 big 16g bored .20 head work, front mount, greddy bov.
The car came with a manual boost controller that didn't work at all. The car will run 15psi with it hooked up but i keep blowing off my inter cooler clamps. I was trying to solve this problem by fixing the boost controller so i could run around on 10 psi. The boost control was running off a 3 prong vacuum connector coming from the intake manifold which also supplied to the bov. I also found that my waste gate actuator is not moving at all when the boost is adjusted. Well after much research on how to install a manual boost control, i found a that the proper way to install the boost controller and went from there. I ran 1 hose off the j pipe to the controller and 1 hose of the controller to the waste gate. And i ran 1 hose from the intake to the bov. Still no control over boost. So i took the hose from the j pipe and ran it straight to the wastegate. Now the car runs good but the turbo docent spool as fast and it tends to creep up at higher rpm's instead of just climbing steady. Also the bov docent seem as loud at low rpm's either.

Now what I am wondering is if the waste gate actuator might not be working properly or is there not enough vacuum to let it work properly. Or am i simply not running the right line to the right parts. I have checked all the lines for damage and have checked boost controller to see if it allows air to flow. It seemed fine. Any recommendations would be greatly appreciated.

The original way it was installed is frowned upon around here (T into the BOV vaccuum line), but what you did to it is the correct way (BOV-->IM on one line, and J-pipe-->MBC-->WGA on another line).

The third way you did it will work, but you'll be limited to the WGA actuation pressure. I'm not sure what it is on that turbo, but on many, it's around 8psi.

I'd go back to the 2nd way. But you should have an aftermarket boost gauge (didn't read your profile - do you have one?) The stock gauge simply won't cut it.

Then you need to make sure you're hooking up the two hoses to the correct nipples on the MBC. It won't work right if you get it backward.

If your couplers are blowing off at 15psi, you need to fix that. They should hold up to 20psi no problem. Do a search on "t-bolt clamps" if you have worm-gear hose clamps. The t-bolt clamps will clamp with much more force. Another option is to get your IC piping (the end that the coupler pops off of) beaded so that the clamps have something to grip. If they're already beaded, maybe try new clamps (cheaper) or go for the t-bolt clamps (better but more $$$).

Do a boost leak test (search for this, as it's been covered thousands of times on this forum). The tester costs a few bucks to make. It will identify leaks in your intake between the compressor and intake ports on the head. Leaks will cause you to run rich under boost which will rob power and hurt fuel economy.

If you post a picture of the MBC or find a pic of a similar one, we can figure out which nipple goes where.

The rise in boost as rpms increase may be your MBC issue, or it may be creep. Before we get to that, you need to fix the blown coupler issue, get a real boost gauge, get the MBC setup verified, and do a boost leak test.

Keep us posted!

 

[vince_w2004]

Wow!
I am glad ive got some answers thank you.
Yes i do have an after market boost gauge on the A pillar that works great.
The boost controller is a crappy ebay controller
<a href="http://tinypic.com" target="_blank"><img src="http://i19.tinypic.com/52xqc8j.jpg" border="0" alt="Image and video hosting by TinyPic"></a>
The car is running a bit rich.
I am planning on going to buy the supplies tomorrow for the leak tester. And head off to diesel supply for the rest of the T bolt clamps but since id worked on the piping problem this past weekend it hasn't blown off yet.
Let me know what u think about the controller.
Another question is.... does is diaphragm rod suppose to to move the waste gate flipper up and down when turning the controller from + to -

 

[oldman]

Just to add to Mack's post,

1. That is a shitty bleeder MBC, I have seen many having problem even with the original turbo smart unit. Get yourself a reliable ball and spring MBC.

2. Sounds like you have boost creep which is to be expected with your 16G.

 

[kenamond]

The upper picture looks like a ball/spring MBC. The bottom one looks like a bleeder type. Maybe oldman has experience with the upper one and knows it's a bleeder type.

If you have the upper model, unscrew the knob all the way out and pull it apart. There should be a spring inside with a ball under it. Make sure nothing goes flying across the room. The MBC housing should also have a very small hole drilled in it somewhere.

Also, if it's the upper type, the j-pipe vaccuum line goes to where the black arrow is. The other nipple goes to the WGA.

If the MBC is a bleeder type, I recommend getting something like a Joe P IL (what I have) or similar for $50. There are others that are cheaper or more expensive, but I'd search the forums for types that folks have had good luck with. If you're tight on cash, you can make one, too (more searching).

And the WGA arm should extend when the WGA sees its actuation pressure. This should turn the lever on the turbine housing which opens the internal flapper. If you have a pressure tester, you can pump up the WGA nipple until the arm starts to move. That'll tell you what the actuation pressure is for the WGA. You can also do this during a boost leak test: put a vaccuum line straight from the j-pipe nipple to the WGA (like your 3rd setup in your original post), pressurize at the compressor inlet SLOWLY with someone watching the boost gauge, and watch the WGA arm. When it starts to move, have the person watching the boost gauge tell you what it was reading (or tell you when you've reached 20psi). This may not give an accurate reading if you have bad boost leaks, but you should atleast be able to see if it moves at ~8psi.

And if you want to know what boost creep is, there is a tech article called "How to cure boost creep by porting" or something like that.

 

[oldman]

Mack, that is a knock off of the Turbosmart unit, it's a bleeder and the top and bottom pictures make up one unit.

 

[dsmpokolm]

Throw that boost controller in the garbage. I had the same one and it is designed to be an in cabin boost controller. I have had one and it didnt work at all, friend also bought one at the same time and same results. Go out and buy a good boost controller. I have the 16g also and have boost creep issues too in higher gears and higher rpm. Doesnt bother me though

 

[vince_w2004]

Yes its one whole kit but im only using the valve not the splitter.
If the arm doesn't move what so ever when its connected to the flipper handle or not, would that mean the actuator is bad, or just not enough vacuum pushing it. It doesn't seem like much air is passing through the line coming off the j pipe.
Yall are really helping me answer some questions thank you!

 

[kenamond]

Yes its one whole kit but im only using the valve not the splitter.
If the arm doesn't move what so ever when its connected to the flipper handle or not, would that mean the actuator is bad, or just not enough vacuum pushing it. It doesn't seem like much air is passing through the line coming off the j pipe.
Yall are really helping me answer some questions thank you!

Did you pressure test the actuator?

 

[vince_w2004]

I searched the forum on how to do that but didn't find anything. I am assuming its the same as pressure checking the intercooler piping. I don't think the actuator is bad though, i have a weird feeling that it isn't getting the vacuum needed for it to work. But i want to go ahead and pressure check it as well. Is there a How To?