My Z Won't Rev

[NCdatsunZ]

Ok Should I just plug it up?

[SteveJ]

PCV = Positive Crankcase Ventilation. If you have a valve on it, it is not a vacuum leak. If you plug it up, you will allow pressure to build in your crankcase where you do not want pressure.

[Captain Obvious]

Those are great engine bay pics. However, even with those great pics, nothing jumps out (to me at least) as a glaring issue. Yeah, the PCV isn't connected and it is a "vacuum leak", but it's a leak that is always supposed to be there and accounted for. The only difference with not having it connected up right is that you will pull in unfiltered air into the balance tube instead of pulling air out of the crankcase. I'm not sure which is dirtier.

After the car gets up to operating temperature, and the choke is completely off, if I spike the accelerator it bogs down. If i hold the accelerator down about halfway it bogs down and eventually dies. If I feather the throttle and get the rpms up to about 2000, then spike the accelerator it will rev, but with quite a bit of smoke coming out of the exhaust.

So let's recap a little. The problem you're chasing is that you press the gas and the engine dies, right?

You're running two turns down on your nozzles... Why? What tuning did you do to determine that's where you should be? Have you tried more? Fewer? I've generally found that two turns isn't enough, especially in the winter.

Also, did you ever borrow a timing light and check the ignition timing?

[Captain Obvious]

Forgot... You can make your system a little simpler just to rule out a few more variables.

You can temporarily remove the hose that goes between the balance tube and the throttle opener control valve and cap off the nipple at the balance tube. That will remove the possibility any air leaking through the throttle opener system.

You can also do the same thing with all three hoses that go to the anti-backfire valve (the little one, and both large ones).

Then once you have got to the root of the problem, you can put that stuff back on. Who knows... You may have a significant leak straight through the anti-backfire valve. :bulb: