• 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

TR6 Carb switch

Share this page

R

Rob DeScherer

Senior Member
Offline
I own a '74 TR6. The previous owner had removed all of the emissions aparatus except for the carbon canister. All of the vacuum tubes that run between the carbs, the distributor, and the thermostatic valve had been removed. My car has never idled properly, even after having the carbs professionally rebuilt.

Could I replace my carbs with those from a '69 0r '70 car and remove the thermostatic valve and have the car run properly? Sorry for sounding so naive.

Thanks for your help.
 
Are you still running points? If yes then check your distributor to make sure that the upper bushing is doing it's job and does not wobble and that everything else in it is as it should be. I have a 74 with none of the emission system left and nothing hooked up as you describe and my car idles perfectly.
 
The thermostatic vacuum switch won't have any affect on anything if the vacuum tube from the bottom of the front carb to it and the tube from it to the distributor have already been removed. You might as well leave it.
However if you give a little more detail about the idle other than not properly we might be able to come up with a solution. In the mean time check for any vacuum nipples on the carbs that are not either capped off or connected to something and cap them. However You do need to have the valve cover connected to at least one if not both of the of the carbs and the Carbon Canister (CC) if you still have it as you say.
My CC has been "relocated" so to speak.


But whatever you do do not cap or seal the nipples like the one I show here colored red...Never.
 
Poolboy --

Thanks for the photos. What year is your car? Are you running any vacuum between the carb and the distributor? I will come back with some better details.

Thanks.
 
No vacuum retard on the 73 in that picture. The retard is not necessary. It was really just one method TR used to obtain US emission compliance back in the 70's.
I had a 74 for a few years and as you may know, it had the most complex emission vacuum plumbing of all the years.
On that car some of it was connected properly and some of it not at all when I bought the car.
Pretty much on my own, I began to rearrange things and observe the effect.
Although there is more I could have eliminated such as the Tkrottle Bypass Valve, the distributor's vacuum retard and the Thermostatic Vacuum Switch, this is where I stopped. Knowing then what I know now I would have.

THE 74:

 
Back
Top