• Hey Guest!
    British Car Forum has been supporting enthusiasts for over 25 years by providing a great place to share our love for British cars. You can support our efforts by upgrading your membership for less than the dues of most car clubs. There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Upgraded members don't see this banner, nor will you see the Google ads that appear on the site.)
Tips
Tips

ZS water choke question for Tony Barnhill.

Share this page

G

Guest

Guest
Guest
Offline
Tony,

I was reading about the Zenith-Stromberg water chokes on your web site. I took the heat mass off to check that the heat spring was working properly and it is working. My question is about that orange plastic fast idle piston assembly. It's white on my carb, but the same set up. Mine does not want to stay out when the choke is on. When it is cold and I pull the throttle cable the piston pops out and the fast idle stepper springs into position, but the idle linkage spring tension pops it right back in. I checked the alignment behind the black spacer and all is good there. So I get no automatic fast idle. I have to hold my foot on the pedal to achieve a fast idle. Isn't it supposed to stay flush with the end of the orange housing until the engine warms up and the choke is released? Is that piston part replaceable or fixable?

Thanks in advance.
Stirkle
 
This may not answer your question entirely but with my TR8s carbs (they also have water chokes)it does not immediately go into a fast idle either. It sort of warms up into a fast idle if that makes sense. Which, with an all aluminum engine that is slow to warm up and really cold weather, that is not necessarily a bad thing. /bcforum/images/%%GRAEMLIN_URL%%/wink.gif
 
This may or may not help as well, but Haynes actually puts out a thorough manual on Weber/Z.S. that really breaks down the confusion. I have had some tuning success thanks to the book, I have the same water-choke on the Jaguar, and I have always been told it is a Must-Have reference for Brit Car owners. If you like I can try to send some information on the auto-choke, I am guessing you have 175-CDse2's? Let me know if you need any pages or procedures.

Brian
 
Thanks Shawn and Brian,

The water choke works and the car actually starts very well when cold, but the fast idle piston inside the round plastic housing does not want to stay out. It sets itself but can be pushed back in too easily by the accelerator return springs. I was hoping that the part was replaceable.

Tony's website is very informative about the choke:

https://www.theautoist.com/zs_water_chokes.htm
 
Back
Top