Correct Duty Cycle Procedures for CIS-E

[ps2cho]

3) Detach the purge line at the electric switchover valve and seal. On my car, this valve is mounted on the inner wall of the left fender, adjacent to the ABS controller. The subject line is black tubing with white stripes.

Is there a picture of this purge line? I am a little confused over it.

Is it necessary to remove this prior to adjusting the mixture for My 1988 300TE. I want to make sure I am setting the mixture correctly because I am having some trouble getting a correct reading.

This is the step that I WAS taking for my 1988 300TE (California)
1. Ignition on, engine off
2. Go to diagnostic box, press and hold button for 4 seconds to read error codes (none)...then press and hold for 7 seconds. Red light should be solid now.
3. Start car
4. Put negative end of DMM into Pin 3 of X11 connector
5. Adjust CCW = lean, CW = Rich.
6. Adjust until reading oscillates around 50%.

Are my steps correct? As you can see I did not do this purge valve thing...

Much appreciated,
Robert

[ps2cho]

Nobody knows?

[stevebfl]

The issue is to avoid the varying effects of differing volumes of purge. In reality unless its real hot out there is usually no purge at idle and the various personal opinions of where to set lambda have more effect than purge. I only disconnect purge when faced with a problem.

[ps2cho]

Originally Posted by stevebfl

The issue is to avoid the varying effects of differing volumes of purge. In reality unless its real hot out there is usually no purge at idle and the various personal opinions of where to set lambda have more effect than purge. I only disconnect purge when faced with a problem.

Other than that, are the rest of my steps correct?
My 260E is right on the verge of passing the smog only failed the HC by 20...so I think if I can get the mixture dead on and get an oil change she will pass. That's why I want to make sure I am doing it 100% correct.

[stevebfl]

Your question means you aren't fully understanding what is happening. There is no better mixture. Whether you set control at 50% or 40% the car runs exactly the same, unless it ever runs beyond control.

Setting to 50% mean the car can correct equally for deviation of mixture both lean or rich. Try it. Set it to 50% watch the control needle goes rich lean rich lean etc etc. Now richen it to 40%, watch it, needle goes rich lean rich lean etc etc. The actual mixture has not changed as the system compensated for the wrong correction. As long as it is in control (rich lean rich lean) the mixture is the same.

The exception and the reason I prefer 40% is that all dynamic mixture is based on the settings not control. This means that when cold (before control) the car is set richer, sudden accel is based on settings as the system doesn't react that fast. But for constant state it make no difference what you set it too till you run out of range at either 0% or 100%. Any setting that allows control is in effect the same.

[ps2cho]

Originally Posted by stevebfl

Your question means you aren't fully understanding what is happening. There is no better mixture. Whether you set control at 50% or 40% the car runs exactly the same, unless it ever runs beyond control.

Setting to 50% mean the car can correct equally for deviation of mixture both lean or rich. Try it. Set it to 50% watch the control needle goes rich lean rich lean etc etc. Now richen it to 40%, watch it, needle goes rich lean rich lean etc etc. The actual mixture has not changed as the system compensated for the wrong correction. As long as it is in control (rich lean rich lean) the mixture is the same.

The exception and the reason I prefer 40% is that all dynamic mixture is based on the settings not control. This means that when cold (before control) the car is set richer, sudden accel is based on settings as the system doesn't react that fast. But for constant state it make no difference what you set it too till you run out of range at either 0% or 100%. Any setting that allows control is in effect the same.

Okay....Then why does a difference of lets say 40% or 60% make a large difference in the smoothness of the idle? The engine just "sounds" happier when set to a certain mixture setting.

Thanks