Idle switch calibration on venturi (tranny solenoid position)

[AndrisV]

Good evening!

There is contradicting posts on forum, about adjustment of idle switch on venturi. As far as I remember from quite a few sleepless nights of combing forums, there are two main versions:

1) Idle switch should break as soon as throttle plate lifts off throttle stop;
2) Idle switch should break at 1200 RPM.

Question is - What is CORRECT position of automatic transmission solenoid, when a driver puts car in gear and stays stationary on brake without touching GO pedal?

I'm curios, because, If I set idle switch to break as soon as throttle lifts off throttle stop and driver engages gear, throttle is moved by dashpot or solenoid (does not matter, it is moved) to compensate engine rpm for a converter drag. So, at that point transmission rises modulating pressure. I think it should not be risen as long as car is not really moving under load (no touching of GO pedal).

Am I correct?

If so, version about 1200 RPM could be better. But then again, how to set that. Simply rise rpm until about 1100-1200 stationary via throttle and then adjust idle switch, or there are other correct methods?

Very big thank's to the community, I'ts my first rodeo with injection pump on auto.


P.S.

Going through quite a rough few days at workshop with W113 69 SL280 US, came to me with simple task of adjusting fuel injection.

So far:

Venturi stop, dashpot, idle solenoid, linkage rods - adjusted completly crazy, the usual;
Mess with shims under baro "mushroom" on pump;
Ignition 010 distr. set to 8deg BTDC@ idle, so it pings on upper rpm range. Not yet sure about rpm/vacuum valve controller, does it work at 2200 rpm;
Transmission slips in 4th; Suspect modulating pressure was adjusted by tranny shop on completly crazy adjusted engine with weak vacuum;
Destroyed thread on intake manifold for transmission vacuum pipe (hey, that's a nice idle controller);

And I suspect, that the list will grow in a few days

[Benz Dr.]

I think you have the right idea. You should keep in mind that the constant speed solenoid will move the throttle linkage when the car is in gear so this is what I do. With the engine off but the ignition on, I move the throttle linkage by pushing on the CSS until it is fully extended. Using a test light, I set the throttle switch so that the test light is still on in the fully extended position. Anything beyond that position and your light should go out. 

[ja17]

Yes at idle the solenoid moves the linkage to the back (rear) position. The switch can be set to open at 1,000 to 1,200 rpms. Setting it just after idle may cause problems since idle is not always constant. 1,000 to 1,200 will give you some cushion in case your idle is a bit high.

The adjustment procedure for the modulator pressure is a bit complicated.  You'll need the adjustment specs., a pressure gauge and the fitting to tap into the test port of the transmission.