naviathan Posted June 4, 2007 Share Posted June 4, 2007 Ok so I'm sure others have noticed this, but when accelerating in my ZX with the AC on the vents switch down to the floor obviously because of the lack of vacuum. This has become quite irritating lately because it's taking longer to get the vents back up into the panel where they should be and I can't for the life of me understand why. The vacuum switch on the manifold is going bad and needs to be changed out soon (keeps making this annoying buzzing sound) but that's just for the idle bump isn't it? Seems when the vents don't want to come back to panel that damned vacuum switch is making all kinds of noise. Could it be leaking bad enough to lower the manifold pressure enough to loose vent control? Ok my real intent for this thread was to ask a simple question. Everything in the Z A/C works on vacuum (especially mine with the Auto Temp Control). Instead of loosing that vacuum when accelerating why not run a line off the manifold and off one of the ported vacuum ports on the throttle body. Place a one way lock in each line so you can only get vacuum and run them to a vacuum canister, then run your vacuum necessary connections from that. Would that not enable you to have vacuum whether on the throttle or off? Quote Link to comment Share on other sites More sharing options...
zcarnut Posted June 4, 2007 Share Posted June 4, 2007 ...Instead of loosing that vacuum when accelerating why not run a line off the manifold and off one of the ported vacuum ports on the throttle body. Place a one way lock in each line so you can only get vacuum and run them to a vacuum canister, then run your vacuum necessary connections from that. Would that not enable you to have vacuum whether on the throttle or off? Yes. But that’s pretty much what Nissan does already. Since the intake manifold vacuum level is a function of engine load and throttle position, a vacuum bottle and a check valve provides a reservoir of fairly constant vacuum despite the intake manifold fluctuations. On the ZX the vacuum bottle is a black plastic container about the size of a quart bottle. The check valve is built into the bottle. It’s sounds like your check valve is bad (common problem). Quote Link to comment Share on other sites More sharing options...
naviathan Posted June 4, 2007 Author Share Posted June 4, 2007 So the black canister that all the vacuum switches and lines for the AC system run into is essentially a vacuum canister. Even with a check valve when accelerating you know longer have a consistent vacuum pull, but if you routed a line off one of the throttle body ported vacuum ports you'd get vacuum even when accelerating as those ports don't pull until the throttle plate is cracked. I think my vents are dropping off so quickly because of the bad vacuum switch for the idle bump. Need to get another one. Quote Link to comment Share on other sites More sharing options...
(goldfish) Posted June 11, 2007 Share Posted June 11, 2007 Is mine the only Zx that turns the ac off when floored? Quote Link to comment Share on other sites More sharing options...
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