Aristo300

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.

nasc300

Checked the wategates?

Aristo300

Exactly what would I be checking for?

Tommyd1919

bad boost gauge? or did you pinch shut the line when you put in on the back of the gauge? If you feel boost through the pipes there is boost... Check for any and all leaks at all the connections..Also check and see if the BOV is bleeding... I have had many a nissans do this

Aristo300

I would hope that the gauge isn't broken as the car is probably twice as slow as the 2JZ-GE. I can't exactly say I feel boost through a pipe, as I'm unsure as to what boost feels like to the touch, but there is air being forced from the turbos through the hot side piping down to where the intercooler would be. [It was removed for the pressure test] About the blow off valve bleeding...... exactly where in the "pressure" route is that. Would that be after the turbos have made the pressure or before?

nasc300

So if turbos are good as you claim, and there are no leaks from the turbo outlet all the way into the intake manifold. Then the only thing that would prevent the system from building boost is the wastegate(s) being stuck open or the the wastegate swing valves being loose from the acuator rod.

Aristo300

We will try and inspect that. I've heard people talk about having a leaky blow off valve... could this cause the pressure to leak?

vipsoarer

if the bov is recirculated like stock then it shouldnt matter, it would just build less boost and be jerky. if it is not recirculated even with a leak it would still make boost it just would be inconsistant boost figures.

Aristo300

Thanks for the reply. We are going to pressure test the entire system tonight looking for leaks.... the intercooler piping has to be the problem. I can't think of anything else that would cause this massive of a leak. The turbos sound very healthy, no smoke, and they sound very good.

SUPRMSC

iTrader: (7)

Check the vacume lines; wastegate not holding boost, or turbos are seized

And they say the 1jz swap is more realiable

Aristo300

I don't exactly see where a boost leak would be considered "unreliable". The 1JZ starts up effortlessly [easier than the 2J] and runs great. We are experiencing a boost leak, not a problem with the motor running. The turbos are fine.... they are spinning, sound great, and are forcing air into the intercooler piping. We haven't checked the wastegates, but I'm unsure if that will even be possible without taking them off. There aren't alot of turbo related VAC lines.... but I'll check over them. It could also be from the blow off valve leaking, but I doubt it would cause this massive leak.

SUPRMSC

iTrader: (7)

If your BOV is leaking or not holding the engine wouldn't run as well as you're saying it is. An air leak is very evident and you should know right away something is wrong. So your car isnt exactly "Running great" when you just said its slower then a stock 2j.

If your turbos are spooling and pressure is being delivered, then there is nothing wrong with the wastegate. There is either an air leak or something is wrong with your motor (compression test).

Aristo300

Saying that the 1JZ is slower than the 2JZ makes perfect sense. The 1JZ is 2.5 liters VS 3.0 liters. It's also lower compression VS higher compression. The 1JZ with the absence of boost would be slower than the 2JZ. I'm doubting the motor is bad......... the pressure simply isn't making it to the throttle body.

soarer479

iTrader: (2)

just double check all the charge piping vaccuum lines are a must to check also could be a boost leak at the injectors one of the most commonly missed problems with a car not making boost

codetoad

iTrader: (2)

I dunno about the injectors in this case - I would check them anyway because you are very right about that- but from what he said, was that the boost wasn't even making it to the throttle body. Hope you get it figured out Duckz