I have a twin turbo 300zx that I need help with. I am willing to pay a fair wage to someone that can help. The car just had new injectors installed and o2 sensors but now there is some type of vacuum leak. The clutch and break pedal are heavier and somewhat of a hsss is coming from under the hood. If someone is familiar with these vg30dett motors and wants to help out go ahead and let me know.

 

where are you located?

there are a pretty good number of vacuum lines stuck in there, and it is likely that something got ripped, or even just forgotten when pulling it apart to install the injectors.

 

I'm in Wesley Chapel.

 

Someone could have also damaged the o-rings on the injectors while installing them leading to a vacuum leak.

 

Oh yeah? I wouldn't have thought you could have a vacuum leak in the injectors

 

not in the injectors, but the o-ring the injector sits in. If the person who installed the injectors didn't do it right, they could have torn one of those o-rings, causing a vacuum leak.

What year 300?

typically, to change the injectors, you have to pull the intake manifold off. When you do that, there is over a dozen vacuum lines you have to remove.
a lot of people will actually remove and by pass most of those vacuum lines for the same of making things more simple. Same thing with the coolant lines. Bypassing and re-routing those coolant lines makes things a lot more simple too.
If you are hearing the hiss, then the leak is rather bad.
Can you narrow down what area it is in when you listen under the hood?

I would bet that it is in the area near the brake booster. Drivers side, rear of the engine, that corner is a cluster fuck of wires, hoses, and vacuum lines. I'd say a majority of the time, I find vacuum leaks in that area.
See if you can look around and find any hoses that aren't attached to anything.

 

I thought it would have been the IACV or the Air regulator or something but it all looks connected. Then I thought that the plenum gasket was put in wrong so I took the plenum back off and reinstalled the gasket but that did nothing. I'm stumped right now. Maybe it is an o-ring on one of the injectors. Would that cause a hiss?

 

by the way it is a '90tt and the egr and coolant lines have been deleted

 

Vacuum leak from injector 0-ring really????WOW
u really dont know crap about Zs

 

Well I could use some help. Can you give me a hand with it?