2G Help! 2G 7 Bolt BOV issues?

[Sylvanessa]

Long story short we were forced into a full engine rebuild on this car. Lifted head. Bad balance shaft bearings. Oil pump. Timing. Etc. Etc. 99 GSX 2G 7 Bolt Auto. Physically almost mint.

Now that it's mechanically done the major issue we have is the turbo starts to spool then dumps all over itself and just stutters and sputters. It has an aftermarket something or other BOV installed from the previous owner. The car once had quite a bit of work done. There are serial cables everywhere and there was an old Venom 400 we found under the center console that was not hooked up. It has a manual boost controller under the dash but we cannot determine whether or not it actually works.

Yeah it's a s**tbox. We are new to DSM and this is the first turbo car we have tried to bring back to life. Any suggestions or help would be massively appreciated. Thanks in advance!

 

[DSMPT]

Now that it's mechanically done the major issue we have is the turbo starts to spool then dumps all over itself and just stutters and sputters.

Sounds like you have boost leak. Before replacing any parts, do a boost leak test and fix all vacuum/boost leak first. That's a must. Do not waste your money for something not necessary.

P.S Please fill your car profile to show us what parts/mods your car has. That would help us to determine the issue.

 

[Sylvanessa]

Filled out the profile.
We do have the boost leak tools.

As for mods.... Engine. None. The rest of it is unknown. ECU may or may not have been flashed. It's apparent from what we found in the car that it was once highly modified. From what we can tell it's all been pulled out at this point. Car runs great at idle and revs.

It's the issue of boost just not working we are trying to figure out.

 

[CKOPOCT]

As DSMPT said, boost leak test is your first stop. Make sure the integrity of the intake system is solid. Once you know that's good you can begin to dive into other possible causes.

 

[steve]

Most of us have made our own tools for boost leak testing.

I used the fitting for my compressor quick connect in a PVC cap the same size as my turbo inlet and a coupler with clamps. Others have used a schrader valve in their setup but I don't have a clamp on tire inflator.

Set your air regulator to something like 10 psi or so initially and use soapy water to look for leaks. Once you fix than at 10psi turn the pressure up to what you think your max boost will be and retest.

Keep in mind that you need at least one set of valves (intake or exhaust) closed in each cylinder for the pressure to build in the intake system.