Hand throttle

[Trnelson]

I’m searching for a hand throttle for a 71 240z, we all know these engines are cold natured and I’d love to be able to set a hand throttle vs sitting in the car for 10 minutes while it warms up. Just wondering if any of you guys may have one or have come up with some DIY solutions. 
Thanks,

 

Tom

[SteveJ]

Why not just use the choke? The hand throttle wasn't for cold weather starts.

[zKars]

51 minutes ago, SteveJ said:

Why not just use the choke? The hand throttle wasn't for cold weather starts.

Yes, the choke lever mechanism is designed to add both richness AND higher idle speed. If you look at the SU’s, the little metal rod with the kink moves with the choke mech and moves a little arm the prevents the throttle blades from getting back to idle hence adding idle speed. You have to adjust the kink angle with pliers to add or subtract the amount of idle increase you get with choke handle motion. Takes a bit of fiddling around. I use one pair of needle nose vise grips on side of the kink as backup, then bend the other side of the kink with another pair. Yes you have to take off the air cleaner to have any prayer of getting in there

I too have dreamed of separating the richness and idle control to get those both “just right” depending on conditions. But that’s what EFI is all about!

Edited March 20, 2021 by zKars

[Trnelson]

I do use the choke, as it begins to stumble I’ll incrementally start “closing” I know it’s not restricting air flow like a conventional choke but lowering the nozzle to allow more fuel i.e. creating a rich mixture, it.  It’s just pig rich when I do that vs getting it cranked, letting it stumble, “close” the choke and then adding a bit of throttle till it’s warm.  If the hand throttle isn’t for cold starts then what’s it for? Cruise control?  I’d doubt that would work very well outside of a perfectly flat road. As @zKars said it would be great to separate the richness for a bit of idle control.  It seems like the plugs get carboned up while warming the engine and it takes a moderate pull or two to get everything cleaned back up and smoothed out. 
Maybe I’ll just cut a stick to length 🤔🤔

[texasz]

2 hours ago, Trnelson said:

Maybe I’ll just cut a stick to length 🤔🤔

Or just get a brick.  lol

[dutchzcarguy]

16 hours ago, Trnelson said:

hand throttle for a 71 240z,

Later on in the production they where left out.. with good reason, if not very good maintained, they are a big danger, thats why you never see them (yeaah yeah.. only in collectors cars.. and they are dangerous in my opinion... but thats just my opinion!!) 

[240dkw]

 

[SteveJ]

Well, you're about 2 hours away from me. Would you like a second opinion on your car? I have been taught by some very good people like @240260280 about how to balance/adjust the carburetors. I might even be able to convince some other Z friends to come over, too.

[duffymahoney]

The SU choke works very well.  Maybe something is wrong?  

[Trnelson]

2 hours ago, SteveJ said:

Well, you're about 2 hours away from me. Would you like a second opinion on your car? I have been taught by some very good people like @240260280 about how to balance/adjust the carburetors. I might even be able to convince some other Z friends to come over, too.

That sound great! I’d like to meet some Z people close to home. I’ve recently completed a refresh and overall it’s running very well, just got home from a 60 mile mountain cruise with almost no traffic so plenty of opportunity for spirited driving. I do know that my throttle shafts are worn, I’m in the LONG Ztherapy line, so I do have a bit of a vac leak there, maybe that’s a contributing factor. Let me know a good time and I’ll come on down. 
Thanks for the offer and I look forward to hearing back. 
 

Tom

[Zup]

7 hours ago, Trnelson said:

so I do have a bit of a vac leak there, maybe that’s a contributing factor

It is.

[Trnelson]

@zKars I got a chance to fool around with the linkage yesterday and that has made all the difference in the world!  I initially overshot the runway and full choke had me at about 4k RPM, probably not a great setting for a stone cold engine...  I'm still dialing it in but I have made a huge improvement from where I started.  One question:  when adjusting the cable do you shoot to have zero slack in the arm that opens the throttle blade?  My initial setting after bending the linkage was no slack but that's where I wound up with too much throttle.  I put a little slack in it and it came down a bit but I'm not sure if it will be enough with the bend I put on the linkage.  Right now I'm thinking about straightening the linkage a little bit and getting the slack back out of the cable since it seems that the first 1/2 or so of the cable travel is what opens the throttle blade.