Automatic transmission idle stabilizer

[DTZ]

Hi All,
I just bought a 1971 CS 2800. I has the weber conversion, and no way to up the idle when at a stop. The car has a vacuum canister and some sort of electrical relay swich that i think was on the origional Zenith set up. Is there a weber add on for this? Any ideas?? Also the weber's have a port and wire on them that does somethng to the fuel, as it clics when I turn the key to on..fuel heater?

 

[Stevehose]

You can up the idle with the throttle plate screws on each carb using a synchronmeter. Then adjust the mixture screws after this. Repeat until desired idle rpm is reached - mixture is always the last adjustment here. Make sure the carbs are balanced at idle and 3k rpm.

Where is the vacuum canister-under the battery? If so this is the fuel vapor recovery tank. One hose goes back to gas tank, the other to the air cleaner.

The port and wire is your fuel shutoff solenoid, this keeps the engine from running on when switched off. The relay you refer to is likely the one that powers this and the electric chokes.

 

[stphers]

I think that what he wants is something to bring the idle up when in D at a stop, nothing really exists to do this with a carbed set up. You might look at the decel valve that I think were on the 74's as part of an emissions thing. That was vacuum operated and allowed the idle to come down slowly, not abruptly That might help you with your auto..

On one car that I used to work on that was an auto, it was a fairly fine line with how much idle speed to give it, how much advance to give it, mixture to get it to idle ok when in D at a stop light and when it was in P Every car was a bit different

Thanks, Rick

 

[HB Chris]

The decel valve was in all US/NA market coupes before they began adding more emission solenoids but they are probably frozen in place by now. You have to be careful with opening throttle plates because if they are open too much at cold start the vacuum will upset the cold idle circuit per Carl Nelson.

 

[DTZ]

Here is the parts I mentioned. The Vacuum canister will up the idle at a stop when the transmission in at a stop with load on it. the electric regulator is link to the transmission , and is activated by what position it is in to have the vacuum increase to up the idle when on load, in gear. This was probably parts from ta Zenith set up.

 

[HB Chris]

That is designed to slow return of the throttle to reduce emissions, controlled by retard vacuum and round valve, found on all US coupes, it does not hold idle however.

 

[DTZ]

Thanks for the info! I guess I'll stat with the carb tuing. It's hard to have a idle when in drive drive with the brake on., as th e rpm's are low.

 

[HB Chris]

A friend had this issue recently and he had significant vacuum leakage of the carb bases which is a known weakness. Shoot some carb cleaner around them with engine running and see if idle increases.

 

[bengal taiga]

Hi All,
I just bought a 1971 CS 2800. I has the weber conversion, and no way to up the idle when at a stop. The car has a vacuum canister and some sort of electrical relay swich that i think was on the original Zenith set up. Is there a weber add on for this? Any ideas?? Also the weber's have a port and wire on them that does somethng to the fuel, as it clics when I turn the key to on..fuel heater?

There were add-on solenoids that could be "adapted" to address this issue. I vaguely remember one on a ‘72 Bavaria, but that was decades ago. If I remember correctly, Holley, AC-Delco and Autolite produced step up solenoids to increase idle speed in order to handle the significant compressor loads imposed on small displacement engines in the ‘70s. I have not searched for any related part numbers, but plenty of images support my recollection. Here is but one link for a bracket and solenoid. https://www.summitracing.com/parts/qft-49-148qft I am confident there are many more.

One obvious problem is the fact that your engine uses two carburetors. I can’t recall whether one solenoid can be employed to control both carburetors, but I seem to recall only one was used for three carburetors on a certain Dodge "six-pack ".

 

[Stevehose]

Perhaps your engine needs tuning so that it can perform properly with the auto trans as intended?

I have a solenoid on my linkage at the block to bump my idle for the a/c compressor at idle; it is not strong enough to open the carbs without assistance from the pedal, but it will hold it open once engaged.

 

[HB Chris]

Tuning should solve this issue.

 

[bluecoupe30!]

I agree, all systems must be in synchrony to enable an Automatic to idle well when warming up, when at the stop light, when coming back to park. Everything, like correct valve adjustment, being certain all ignition wires are working as they should, and especially, make sure those Weber carbs are clean and no chambers or adjustment orifices are gummed up such that adjustment would not have the desired effects. Cars are 50+ years old, lots of deferred maintenance on cars that have sat a long time. But good news is, much of these drivability issues can be solved with a good cleaning, tuneup, attention to details that you will always find here. Good luck and keep us posted!