What is this and what does it do?

[280ZWarrior]

I just did a auto to manual conversion, header, and exhaust. It seems that when my Z was an automatic, the idle was smoother. I blocked off my egr so I know it isn't that. I'm guessing it is a vacuum leak and it might be this...

Any ideas what it is and its function? It seems to be missing a vacuum hose to somwhere...

Thanks in advance,

Mike

[geordieggg]

I'm not 100% sure, I've gto the same on my car and it's not hooked up either. I'm guessing it's vacuum controlled (obviously) and it adjusts the throttle slightly, probably only to help with cold starts (to let more air past the butterfly).

My best guess............

[Grim]

anti-stall dashpot. it was on manual tranny cars only

[Grim]

there are no hoses hooked up to it. thats just the way it is supposed to be.

[280~Master]

Its the dashpot and it helps the engine come to a softer idle when the foot is released off the throttle. Don't worry about it. It is probly bad by now so remove it and drive on. Not having it won't hurt anything.

[280ZWarrior]

anti-stall dashpot. it was on manual tranny cars only

It can't be on manual cars only because mine was an automatic from the factory.

When I put my finger ofer the top and move the throttle linkage, it creats a suction. That is why I figure it has/had a vacuum connection.

The reason I'm asking all this is because when I push in the clutch to shift while driving, the car revs up about 500rpm...

[sblake01]

It's on all 280Zs and 810 regardless of transmission. I don't know where Grim got the notion that it only existed on AT cars. No vaccum connection. They removed them when they came out with the ZX and the Maxima. All it does is is what 280~Master said. And from your description, yours is working properly. Is your car by chance a California car. I only ask because the 500rpm thing you speak of is symptomatic of a badly adjusted altitude corrector but those are only on the California cars.

[280ZWarrior]

It's on all 280Zs and 810 regardless of transmission. I don't know where Grim got the notion that it only existed on AT cars. No vaccum connection. They removed them when they came out with the ZX and the Maxima. All it does is is what 280~Master said. And from your description, yours is working properly. Is your car by chance a California car. I only ask because the 500rpm thing you speak of is symptomatic of a badly adjusted altitude corrector but those are only on the California cars.

As a matter of fact my car did come from California! That's amazing! You must really know your stuff. Can you tell me where is this altitude corrector located and how to properly adjust it?? It is quite annoying when I want to shift or just roll to an idle...

So basically I can just remove that piece that I posted a picture of? It won't affect anything important (ie: Emissions, MPG, Air/Fuel mixture)?

Thanks again,

Mike

[sblake01]

I shouldn't have said badly adjusted when what I really meant was malfunctioning. The altitude corrector is located on the drivers side near the hood release. It compensates for alititude by leaning the fuel mixture by 6% above 3675 ft. When they don't work properly, they can cause the idle to hang up for a while before it settles to normal. You could replace it but most commonly, people just disconnect it which solves the idle problem but you lose the altitude compensation. Part number 22612-N4800.

[First Gen Z]

Stephen, The 79 ZX also had the dashpot.

Mike, The dashpot does not have any vacuum connections. It's function is to keep the throttle from slamming shut when you take your foot off of the pedal. Leave it there.

[sblake01]

Well, that's kind of a grey area. Some 79s, maybe the early ones, had them. My 79 810 has one but I've seen other later prod date 79s, both ZXs and 810s that didn't. Instead, they had a type of spring arrangement that did basically the same thing. But I do agree, leave the dashpot.

[TomoHawk]

My 280Z with Fed. emmissions didn't have the dashpot, nor do I see any room where it should be located (I'm constantly comparing mine to other "stock" cars.) It runs fine nevertheless. I'm wondering about the BCDD myself lately ( as in do you really need that?)