Hand throttle?

[Arne]

My SUs arrived yesterday. A decent set of 4 screw round-tops on E88 manifolds. After searching and studying old posts and pictures, I think I've got it all figured out - what connects where and such. But I noticed that the center linkage between my carbs doesn't look like other pictures, it seems to have an extra lever near the front carb. (See pics below.) Would this have perhaps been for the optional hand throttle?

[montoya_fan01]

No, the hand throttle cable connects to the accelerator pedal linkage.

Your pic looks like the linkage on my car.

[Mr Camouflage]

My SUs arrived yesterday. A decent set of 4 screw round-tops on E88 manifolds. After searching and studying old posts and pictures, I think I've got it all figured out - what connects where and such. But I noticed that the center linkage between my carbs doesn't look like other pictures, it seems to have an extra lever near the front carb. (See pics below.) Would this have perhaps been for the optional hand throttle?

What extra lever?? looks normal to me. each carbie has its own choke. you should have 2 choke cables comming from the choke lever.

[texasz]

No, as stated above the hand throttle connects to the gas peddle inside the car...search for some old posts detailing this out.

As for your "extra" part, if you are talking about what I have highlited in the attached pic that is normal and connects to nothing.

[Arne]

As for your "extra" part, if you are talking about what I have highlited in the attached pic that is normal and connects to nothing.

OK, that's the one. My eyes must be getting bad, I had gone to ZTherapy's site and could have sworn that the linkages pictured there didn't have it. Of course, when I go back today and really stare at them,now I see it.

So I just let it rattle around there?

[mdbrandy]

No, as stated above the hand throttle connects to the gas peddle inside the car...search for some old posts detailing this out.

As for your "extra" part, if you are talking about what I have highlited in the attached pic that is normal and connects to nothing.

Doesn't that linkage connect to the deceleration dashpot that many have removed from their cars?

[sblake01]

Thanks, mdbrandy, I was going to say that but it's been a while since I owned a 240 and my recollection was kind of foggy. :surprised

[Arne]

OK, that makes sense. I guess I've not yet seen a picture with the decel dashpot on it. Thanks all.

[texasz]

Doesn't that linkage connect to the deceleration dashpot that many have removed from their cars?

Right you are on both accounts! I have never seen a Z with this item still installed...nor have I even heard of it.

Please tell me about it's purpose and the pros/cons of removing it.

[mdbrandy]

Right you are on both accounts! I have never seen a Z with this item still installed...nor have I even heard of it.

Please tell me about it's purpose and the pros/cons of removing it.

I believe it is a small vacuum valve that "damps" the throttle closure for emmissions purposes. So if you quickly take your foot off the gas, this device slightly slows the throttle closure and allows a little more air into the manifold. This keeps a rich slug of mixture from moving through the system, so you don't get a burst of unburned fuel out the tailpipe.

That's what I THINK it is for. I can't see how it would affect power at all, so it is an emissions device that I dont' see any harm in leaving alone. When I get to actually working on the engine restore on my 240, I'm going to restore the entire air injection system.

My 2 cents.

Mark

[Arne]

Makes sense, I think you're right. What emissions engineers call "drop throttle" conditions are one of the biggest sources of tailpipe emissions.

Hopefully Nissan's solution on the early Z will be less annoying than that of my '96 BMW 328i with a manual transmission - the engine management system on that car holds the engine RPM for 2 seconds before allowing it to drop slowly. Highly annoying when shifting.

[deadflo]

Can someone tell me what purpose the hand throttle served anyway?