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Discussion Starter · #1 ·
Having an issue with my 1JZ VVTi in my '87 not wanting to boost past 10 psi even with an electronic boost controller

Some back story...

Swap was completed last year. Stock engine, Future fab downpipe, 3" exhaust, CX Racing intercooler, Tweakd harness. No boost control hooked up. Ran flawlessly aside from a smoky original turbo with unknown mileage. I would hit around 12 psi in 2nd and creep up to 13-14+ in 3rd and 4th under full load and eventually hit boost cut if WOT in those gears.

Fast forward to this year I did some maintenance and replaced a few things including the turbo, got it rebuilt by Driftmotion with the upgraded internals and larger wheel. They also enlarge the wastegate opening slightly during the rebuild, which I was glad to know since it would help some of the boost creep I was getting before. Once installed with no boost controller it felt extremely laggy compared to before and would only hit 9-10 psi. I've since installed a Turbosmart eboost street and have tried increasing the duty cycle but can't get any higher than 10 psi sustained boost. Raising the gate opening pressure will cause a spike up to 12 psi but settles quickly back to 10 psi.

I verified I have the lines routed correct to the solenoid. Boost leak test seems normal (all clamps are tight). I tried unplugging the electrical connecter to the stock BOV and that gave me a ton of flutter and seemingly quicker boost response, but no more peak boost. Tonight I just shoved a coke bottle cap in the recirc pipe to try and block it off, it fit very tight but I was surprised when it did nothing for peak boost. Could the IACV be leaking boost if it isn't working right? Or could it be the wastegate? Not sure what to try next

Sorry for the long post, longtime lurker here and I've searched a ton of threads but am at a loss here. I appreciate any help! Thanks
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I would try a simple manual boost controller closed all the way or even remove the line going to the top of the gate and see if you get more than 10 psi. That should at least tell you if it's a leak somewhere or boost controller isn't working. Be carefull.
 

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Discussion Starter · #3 ·
That's a good idea I'll try removing the line to the gate, waiting on some vacuum line caps I ordered to cap the pressure source too. Today I set the gate opening pressure on the boost controller to 11 psi. This gave me a boost spike up to 13 ish psi then falling back to 10 psi. Just did a boost leak test with the hose to the IACV taken off and the IACV is fully closed so I don't think that is the issue. Maybe a bad solenoid, I dunno. I'll report back once I test with nothing hooked up to the gate
 

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Not suggesting these things are your issues, but I recently had boosting issues and I had a clogged Cat and oddly, air was leaking past the injector grommets. I replaced the Cat, which helped and now I'm waiting on new grommets to replace those and then I'll re-test to make sure I got all the leaks.

(I blocked off my intake and made a block off plate for the downpipe, so I was able to pressurize the entire system; this is how I found air was leaking past the injector grommets. I never would have thought to look at those otherwise.)
 

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Discussion Starter · #5 ·
Thanks Jonny, all good thoughts. Were you able to get your issue fixed? I have a no cat and the injector grommets are brand new so no leaks there.

I think I narrowed down the issue last night. Unplugged the wastegate line (so no pressure to wastegate & it won't open) and boost shot up to 15+ psi quickly before I let off. Felt great for that split second haha. So basically that tells me it's not a boost leak or vacuum leak anywhere, it's the solenoid not bleeding off any air, so it's gotta be defective

Now my problem is I purchased from Amazon and apparently all Amazon sellers are basically blacklisted by Turbosmart! And they don't offer support for any products bought from any "unauthorized sellers". Fuck me, now I'm stuck with a useless (and likely Chinese knock-off) boost controller. I emailed Turbosmart and waiting to hear back. Anyone else get trapped by shady sellers and/or counterfeit parts? Really regretting not buying from Turbosmart directly...
 

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Thanks Jonny, all good thoughts. Were you able to get your issue fixed? I have a no cat and the injector grommets are brand new so no leaks there.

I think I narrowed down the issue last night. Unplugged the wastegate line (so no pressure to wastegate & it won't open) and boost shot up to 15+ psi quickly before I let off. Felt great for that split second haha. So basically that tells me it's not a boost leak or vacuum leak anywhere, it's the solenoid not bleeding off any air, so it's gotta be defective

Now my problem is I purchased from Amazon and apparently all Amazon sellers are basically blacklisted by Turbosmart! And they don't offer support for any products bought from any "unauthorized sellers". Fuck me, now I'm stuck with a useless (and likely Chinese knock-off) boost controller. I emailed Turbosmart and waiting to hear back. Anyone else get trapped by shady sellers and/or counterfeit parts? Really regretting not buying from Turbosmart directly...
It sounds the reverse to me. Presuming the solenoid you are referring to is the wastegate actuator. It sounds like it is opening too early and causing the exhaust to go out the tailpipe without hitting the turbo. When you disconnect it, the wastegate does not open, so you get the additional boost.

The actuator that I purchased for my car came with six sets of springs. The default set that was installed when purchased opens at 30 lbs., which is too high for my use. I tested this by connecting it to the air compressor, and increased the air pressure until the shaft moved. It started opening at 20 lbs, and opened about half way. At 30 lbs., it was fully open.

I am far from an expert when it comes to many things, but these are my observations on the subject. Hope they help.

David
 

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Definitely sounds like a boost controller issue, which should be the easier of the problems to fix. I have used a 20 year old Greddy MBC on my mustang and now my Supra and its has never failed me yet.
 
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Are we using the terms solenoid, wastegate actuator and boost controller interchangeably? I’m easily confused as to when we’re talking about the same thing vs. totally different components.

The OEM actuator that was on my original CT26 turbo opened when I blew on it. Seems to me that it would have opened the wastegate too quickly causing the turbo not to reach the desired output.
 

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Discussion Starter · #9 ·
Definitely sounds like a boost controller issue, which should be the easier of the problems to fix. I have used a 20 year old Greddy MBC on my mustang and now my Supra and its has never failed me yet.
Haha they don't make 'em like they used to! I have a manual boost controller on order that I can play with for now. Still not sure how to resolve the Turbosmart eBoost since I'm out $260 and have a broken solenoid that I can't return or get replaced under warranty
 

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Discussion Starter · #10 ·
Are we using the terms solenoid, wastegate actuator and boost controller interchangeably? I’m easily confused as to when we’re talking about the same thing vs. totally different components.

The OEM actuator that was on my original CT26 turbo opened when I blew on it. Seems to me that it would have opened the wastegate too quickly causing the turbo not to reach the desired output.
I'm not, to me the solenoid is the 3-port electronic solenoid in the engine bay. That's what I'm 99% sure is defective and causing the wastegate actuator to see the same pressure since it's not bleeding any pressure off like it should with the duty cycle turned up. Sorry if this post has been a little wordy, trying to explain things best I can :)
 

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Discussion Starter · #11 ·
Are we using the terms solenoid, wastegate actuator and boost controller interchangeably? I’m easily confused as to when we’re talking about the same thing vs. totally different components.

The OEM actuator that was on my original CT26 turbo opened when I blew on it. Seems to me that it would have opened the wastegate too quickly causing the turbo not to reach the desired output.
I had the same issue back when I was running a 7M, damn thing built boost so slowly
 

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Haha they don't make 'em like they used to! I have a manual boost controller on order that I can play with for now. Still not sure how to resolve the Turbosmart eBoost since I'm out $260 and have a broken solenoid that I can't return or get replaced under warranty
Is this a “manual boost controller”?

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Still not sure how to resolve the Turbosmart eBoost since I'm out $260 and have a broken solenoid that I can't return or get replaced under warranty.
I browsed back over the thread and didn't see the reason of no return, no warrantly, and will presume it is due to time. Is there anything to keep you from ordering another one, testing your theory, and if it doesn't solve the problem, at least returning that one? Granted, it doesn't solve the money issue, but keep that separate and solve the basic problem.
 

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Discussion Starter · #14 ·
I browsed back over the thread and didn't see the reason of no return, no warrantly, and will presume it is due to time. Is there anything to keep you from ordering another one, testing your theory, and if it doesn't solve the problem, at least returning that one? Granted, it doesn't solve the money issue, but keep that separate and solve the basic problem.
Sorry I might've left that part out. It's past 30 days (by a week) so Amazon won't let me return. I messaged the seller and they won't help me other than say go through the manufacturer, and Turbosmart won't help me because they view all Amazon sellers as "unauthorized"
 

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Sorry I might've left that part out. It's past 30 days (by a week) so Amazon won't let me return. I messaged the seller and they won't help me other than say go through the manufacturer, and Turbosmart won't help me because they view all Amazon sellers as "unauthorized"
I though I read that, went back to find it and didn’t see it. I’d get another one to test your theory. Amazon takes all kinds of shit back.
 
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