My Z has takin on a life of it's own. First a fuel leak that suddenly went away before I could locate it. Then an injector flew the coupe (ohmed at 30) and suddenly spranged back to life after 45 days on 5 cylinders (thank god). Now I have a hissing noise from the drivers side of the engine bay. Is this normal?? I have good vacuum and the noise doesn't change under neutral WOT so I'm not thinking it's a boost leak but hell I don't know. Kinda hopin it wil go away till after the holidays when the cash flow is redirected from presents back to car. Anyhow it's drivin me nuts.

 

Hissing is usually a vacuum leak. How's the idle? It could be a small hose that's come loose. Happy hunting. That injector will go bad again, so start saving to replace it.

 

As far as that injector, I got a line on the nismo 555cc set for 145 per. just have to make it through the holidays. Idle is ok now that all the cylinders are firing again. about 850-900.

 

Possibly a turbo leak? Wastegate vaccum line?

 

Check the turbo outlet pipe. There a 3" long rubber hose with 2 hose clamps that connects the tubo to the piping that runs up to the IC's. If it was a turbo leak, it'd very noticeable under boost. Did you remove the balance tube tocheck #6 injector? Could you've fortgotten to reconnect one the hoses that runs to the balance tube?

 

It's not coming from the balance tube area, it was #3 that was schizo. It does sound like it's coming from the piping area along the side of the motor.

 

Has it seemed to have lost power? If so, then boost leak. If not, vaccuum leak.

 

Found it, What the hell is that damn little sensor directly under the clutch resevoir. sWell that was the leak, I couldn't see till I used a tube to listen for it. There is a T there that came unplugged. Thanks for the responses guys.

 

I believe those are vacuum lines for the clutch booster.

http://www.courtesyparts.com/z32/oe_clutch-boost.html

 

2nd on what 91 said. Those are the vaccuum hoses for the clutch booster.

 

Actually the hose don't make it to the clutch booster. There is a sensor mounted directly under the booster on the fender away from the firewall that it went to. Can't figure what it does though.

 

Thats a vacuum line alright, it is a part of your emissions control device known as an AIV valve. It helps in preventing scavaging by directing air drawn by a vacuum into ur exhaust manifold when the backpressure drops to low. It will stop pulling air in when the pressure builds up again. U have two of them, one on each fender going to each manifold. I think that may be the problem I am having on my '92 NA, it has a had hiss for a while now but not enough of one to cause drivability problems.

 

Hmmm. Partially correct. It is vacuum controlled, but that's not the sensor he was talking about. The AIV solenoid is actually located on the passenger side of the car. The system doesn't inject air into the manifold. If injects air into the midpipe directly in front of the cats. This helps the old style cats burn the unburned fuel more effectively. If one was to upgrade to test pipes with a hi-flow cats, they can remove the AIV/secondary air system.

 

Were are both right and both wrong...for those of u with ur text books i m on pages EF & EC -19 and 20 in the Nissan Factory Repair Manual. Your right about the A.I.V. control solenoid being on the passenger side feder. BUT, I m right because I am refering to the A.I.V. valves themselves. They are controlled by the solenoid, and there is one on both passneger and driver sides of the car. As for the correction on where it actuallsy dumps the air, the manual states air as being sent to the exhaust manifold. EF & EC-20 sec. Air Induction Valve (A.I.V.). Look at the second and fourth lines down. The A.I.V. valve on the right side is located under the clutch master cylinder too. You then again may be right, cause I am using the 1992 manual, it may be different on other models. I think were 2-2. LOL!

 

Could be...I removed mine a couple weeks ago. There wasn't a solenoid on the driver side. The valves themselves are under the fenders. They're covered by the splash shields.

 

Oh ok, i remember your right. The vacuum line does go into the fender. My misunderstanding. Yeah there is only one control solenoid on the passenger side which feeds into two control valves. Would it hurt to remove the system on a NA? What are the benfit/drawbacks of doing so?

 

In order to do remove it, you need to install the newer style cats,or test pipe w/hi-flow cats. The AIV is basically a smog pump. Your car won't pass smog with the OEM cats without thay AIV.