Fast idle?

[laneriddle]

Hi, my '66 Cooper S is running good,except that after driving awhile the idle is much faster than when it starts cold.The SU carbs are newly rebuilt.I removed the PCV valve and plugged the hole in the manifold,I think that helped ,but not sure yet.Any ideas? I sprayed WD40 around the ends of the throttle shafts while the car is idling and it almost stalled out,so I guess they are sucking air? Would that cause the idle to speed up after the car warms up?

 

[dklawson]

A leak that bad around the throttle shafts would make it nearly impossible to set the idle properly. The repair method is to bush the bodies and fit new shafts. For some sizes of SU there are also oversized throttle shafts that can be used to "close the gap" without fitting bushings. Some of these parts are available through Burlen (SU) in the U.K. Professional rebuilders like Joe Curto will also be able to sort this out for you.

EDIT: I noticed you are in VA. In which part of the state are you located?

 

[laneriddle]

Hey Doug ,yea I did figurecout that the shafts weren't the problem,they do leak a little but not enough to cause that effect.it was really as simple as a crummy throttle cable. When I first put the car together after paint,I didn't get a good ground to the body (to much paint) . Before I figured that out it fried my tail light fixtures ,and apparently my throttle cable.I have it all sorted out for now,I'm on the road ,ready for spring.PS, I'm in northern VA,close to Manassas

 

[dklawson]

I'm glad you got this sorted out and that you didn't have to work on the carbs (directly) to fix this. On the road just in time for spring!

 

[M_and_P]

The throttle cable was the issue with my car as well.