Carb Linkage Issue [3000 MkI]

[Bobbee44]

My 1960 3000 stopped dead late this summer. I coasted to the side of the street and could not get it started again after running through my complete list of potential culprits. The car was taken to the closest British car facility and kept for over a week. I was told the rotor was cracked and that was the reason the car had stopped dead. On driving the car from the repair facility, I noted the gas peddle was exceptionally stiff and the idle was very high (1200 rpm). I turned around and returned to the facility. The mechanic lifted the hood and showed me he had installed a spring to assist in keeping the idle low. I did not have any idle issues or return spring issues when I brought the car into the facility. Now, I have about two inches of throttle play as I push the gas peddle, before any change in engine rpm. The return spring at the gas peddle is in place.

I've made sure the two springs on each end of the carb linkage are tight and are not slipping. My question is simply this: What could the mechanic(s) done to the linkage to require an auxiliary spring, to a heretofore well operating system?

Any help in pointing me to a solution would be appreciated.

Bob

 

[DerekJ]

It sounds like the linkage is not adjusted properly. Have somebody sit in the car and press the throttle while you watch what happens in the engine bay. There must be some slack in the system.

 

[steveg]

Here are the linkage adjustment pages from the manual:

 

[why]

Yes but, just replacing the rotor should have made zero effect on the linkage. In addition, you now have a 1200 rpm idle which in hot conditions waiting at lights could exacerbate overheating. Something seems mighty strange.
Jay, '65 3000

 

[rjc157]

Who was the shop I would bring it back where did he put the spring ,find a local club member to see if the linkage is correct

 

[steveg]

If the broken rotor was one of the ones with the brass rivet holding the metal part, those are known to break. Get a couple of new-style red rotors from Advanced Distributors or Moss.

 

[RAC68]

Hi Bob,

I appreciate your frustration and, if I were in the situation I would probably do as rjc157 suggests.

First, whether a standard ignition or electronic setup, a cracked rotor could be the result of using one of the still available bad rotors on the market with a simple replacement curing the problem. However, if the issue was caused by the rotor's intervention with another distributor component, I would also consider a cracked cap or, even more probable, a misalignment or sticking vacuum advance plate. Since any of these additional distributor issues could cause a higher idle speed, the shock caused by the common act of flipping the carburetor linkage for reducing RPMs could, in fact result in the sticking distributor component resetting and, if reinforced by any other observed linkage issue, result in a misdiagnosis as a carburetor linkage problem.

Although my response is purely hypothetical, I would solicit a second opinion form local Healey-knowledgeable friends or club members to gain additional insights and or conformation of my conclusions and planned resolution. After thoroughly evaluating the distributor for unresolved problems and rechecking ignition timing for a correct setting, I would look at and make sure that your carburetor linkage is set per Steve's provided documentation before making the decision whether to make all changes myself or returning to my mechanic with the findings from my investigation.

Last thought, many have had difficulty with sticking choke linkage on one or both carburetors resulting in an occasional high idle from not being fully released. Changing distributor settings and a cold engine would probably involve the use of chock to start the engine. Since no 2 individuals would have apply the same force and extend of pull to the choke, it is possible that the choke linkage could be drawn into an uncommon space and one of the units is not fully releasing.

Bob, these are my rough thoughts based what I would do and look for if confronted by the conditions presented. if I put my trust in a mechanic and paid him for his knowledge and a resolution of my problem and was not satisfied, I would provide him with my dissatisfaction and the information discovered as customer feedback to gain the benefit of his further contribution or make a decision to follow another path.

Good luck,
Ray (64BJ8P1)