shutoff valve quark 81 300sd w126
 

i noticed that since i replaced my ignition on my car it will not start the first time when warm... if i try and start it when warm i mess up my alda pressure and the car will run sliggish until i turn the car off and cycle the ignition switch on and off two time to release the shutoff valve vacuum... where can i test this vacuum issue... does this sound like a bad shutoff valve or maybe vacuum hoses reversed on the ignition

Did you do as I suggested in the other thread and drive it without the brown vacuum line attached to the shut off valve to see what difference it made? Also instead of cycling the ignition switch when it's warm, you should just pull off the brown vacuum line and see if it starts right away.

How do you know you are messing up the ALDA pressure when warm?

yessss sorry about missing that now... i removed the brown line as suggested... but with it removed i have no issue... It only seems to be when the car is park the vacuum from shutting the motor down doesnt seem to be bleeding off or something... When i disconnect the brown vacuum line all is good... but even with it connected i dont have an issue until i turn the car off and back on... then my motor runs sluggish... If i remove the brown line prior to restart it is fine but if i leave the brown line in the shutoff i lose power at startup and while im driving until i unplug the brown line and back in....

so, the shutoff valve is fine, you have a vacuum issue.
reverse the brown lines in the engine compartment. if that does not work, you may have a vent line plugged or connected to a vacuum source.

For some reason the vacuum portion of your ignition switch is not bleeding off enough vacuum when you shut off the engine for a short period of time.

John's advice is good. You could also put a vacuum gauge in line with the brown line at the shut off valve and monitor the amount of vacuum there. It should be 0 when the key is turned on.

switched the lines and still runs fine just doesnt turn off and have to switch them back... should i vacuum test my ignition switch if so what am i looking for

where are the vent lines at... i did remove my 3/2 valve and connected the T connectors to bypass the 3/2 from an egr delete

I'm pretty sure the shut off circuit vents at the ignition switch.

There are 2 shut-off valves in your car. 1 on the injection pump and 1 on the ignition. Your problem is with the shut-off valve on the ignition. I worked on an SD several years ago doing the very same thing. The part that the vac hoses attach to on the ignition is the shut-off valve. It can be removed and replaced.

Here is the part
PeachParts FastLane Mercedes Parts Store - '81 SD Shut-off valve

so did i buy a faulty part... i just put in a brand new one as a complete ignition unit... i replaced the entire unit from my steering wheel that would lock up... ill pull it off today and check it with a vacuum pump

No need to pull it off. You can check it by checking the vacuum levels at the brown line at the shut off valve which I described earlier. t-into the brown line and monitor the vacuum levels in the on/off position.