duowing

Alright, I'm still trying to find my leak that's causing my factory gauge to read around 16-17inHG instead of the full 20 at idle.

First off, I don't think I have a leak at the manifold where it meets the head. I've been testing all the lines that immediately come off the manifold except for the PCV valve. All of these lines have come out as reading 20inHG at idle. So I'm assuming that means that I don't have a leak at the gasket, right?

Anyway, there's the line that comes from the manifold, it reads 20inHG right off the manifold, it goes down to that metal tubing which runs into the boost gauge, and the line that goes to the VCM. I plugged off all the other spots on the VCM and it read 20inHG. I plugged everything in, and then took the big line that comes from the middle of the VCM and goes directly into the AFM boot. The line coming off the VCM reads 20inHG, and if I have it plugged instead of going into the boot it reads 20. As soon as I plug it into the boot my vacuum gauge drops to around 16-17. I have no vacuum reading if I try and test the big hose that runs from the boot to the valve cover, I have no vacuum reading from the hose that runs from the boot to the carbon canister, and I also have about 1inHG of vacuum coming off the throttle body. I've removed the boot it looked fine, I've removed both hoses and just plugged them off to see if that would change anything, with no difference. Any advice on where to start or look would be helpful. This is just really annoying and I can't figure out where my vacuum is going.

Sorry to make such a long post

NismoPick

So... remind me again why you are so worried about these vacuum differences? Is the motor running poorly? And pressures would prolly be different before and after the tb...

snwbrderphat540

yeah dood no big mine reads around 17-18 and runs fine, well actually its been flooding every now and then but im pretty sure its my CHTS sooo w/e

duowing

Maybe I am worrying too much, I just find it odd because of the fact that one night it read fine and then the next day it ran differently. I swapped out my J-pipe today for the one I got from bleach. The one I had got kinda mangled up and was shaped more like a pear than a circle. That did make a bit of a difference in just the way it runs.

The car runs really good as is. I don't know why I'm so worried, maybe it's just because it's an inconsistency. Also I've just been paranoid about very minor details ever since I had my Z31 go wacky.

My idle seems to vary a bit, and my vacuum reading will sometimes vary from my Autometer boost gauge. Also once in a while when I start it, the car will idle poorly and die unless I give it throttle. I remember lww saying it's probably a connection issue, and Rod saying he's always had that even though just about everything has been replaced.

duowing

Alright, I have one final question for you guys. I'm trying to figure out what lines go where to the VCM it seems I messed up.

Anyway it looks like the line that comes off the manifold and supplies vacuum to the VCM has a check valve in the middle which I thought was meant for the EGR. So anyway, I'm trying to figure out which line goes where on the VCM. I know which supplies the signal and which port to plug that in, but which part do I plug in the line for the AAC valve? Does anyone have a picture by any chance?

NismoPick

d00d... do you not have a Haynes manual yet? Imma slap ya if not!

duowing

Yeah I realized how noobish I've been lately. I just found out about the diagrams in the FSM and Haynes. Now I'm feeling dumb because all these weird discrepancies may be just linked to the fact that I have this vacuum check valve hooked up incorrectly.

Thanks for all the help guys. I'll try and stop asking dumb questions.