Having boost issues with my 1JZ SC300.

[Brown Duckz]

Well we finished the swap, after some transmission linkage problems the motor fired on the first try, idled decent, sounded great. No abnormal smoke, no odd noises. Since the first drive we haven't been able to build any boost......... at first I thought it may have been because my friend "vented" the factory blow off valve, but we put it back to stock. We thought it could be the intercooler, but it was pressure tested up to 30lbs and it's SEALED. While the intercooler was off we checked for air being forced on the hot side piping, and there is forced air from the turbos. I'm 100% positive it's not the turbos..... they sound healthy, no death wine, no smoke - and they are obviously spinning air. Our boost reading is coming from a port on the intake manifold. Is there anyone who has any idea on this? I need some help troubleshooting here. Could this be a sensor? Possibly the turbo pressure sensor that's present on the intake side? We haven't yet checked each individual pipe/section of the intercooler route, but even if there was a small leak I'd think there would be some boost being built.

 

[Brown Duckz]

Anyone?

 

[drunk_medic]

Are you using an aftermarket boost gauge? You really need to get one, if you don't have one. Plug it up to the piping between your turbocharger outlet and the intake manifold somewhere. That's a broad range and should provide you with plenty of places to tap into. A simple way to tap is to get a 3-way and some additional vacuum hose. I don't see a turbo pressure sensor doing it UNLESS the sensor is not working and not sending a signal to the ECU, but in that case, if the turbochargers were boosting you would be running extremely lean, and that would not prevent a mechanical boost reading from an external gauge.
You also may want to take your piping that goes to the turbochargers off and see that the impellers are spinning freely. If they are.. you may want to take the turbochargers OFF and look at the exhaust section. The previous owner could have grenaded the exhaust wheels, and we all know that a turbocharger without an exhaust wheel isn't getting you anywhere.
I know you say that you are sure about a few things, but when you are shooting in the dark, it's good to re-check yourself sometimes. I would suggest an intercooler pipe leak tester. It's cheap, and if you pump it up and it isn't holding pressure, you know the culprit.
http://www.vfaq.com/mods/ICtester.html

By the way, that's a nice SC300. I want a '97 manual for a swap. Wanna give it to me?

 

[Brown Duckz]

Well I think the turbos are blown. My friend inspected them and the front turbo is not moving much air, but the rear turbo is hard to examine I suppose. It's either blown turbos are the gates are f-ed up. I've got another set on the way, and hopefully JHOT will reimburse me a little for this.