1973 Pressure Sensor testing 450SL "Suck" test quick question please
 

If I apply vacuum to the pressure sensor, and measure pins 7&15 and 8&10 on the ECU cable harness, should the readings change when vacuum is applied? I mean that is what the device does, isn't it? Or is it no that simple.

Case in point 89 ohms 7&15 15 inches of vacuum applied and the reading stays the same. 356 ohms on 8&10 another 15 inches and reading stays the same.

To start with those readings are correct, what type of running issue are you having?

Car not running. starts, idles for 2-10 seconds coughing and sputtering, then dies. Interestingly, I've noticed that sometimes when I turn the key to "Stop" she gives one more kick.

I had started a thread in the SL section,,

http://www.peachparts.com/shopforum/sl-forum/312331-1973-450sl-starts-cold-valve-squirt-then-stalls.html

Does the engine coolant temp sensor check out? resistance?

Have you checked the trigger points?

Is the HOSE to the pressure sensor in good condition?

at 50 F (shop temp) I measured 3500 ohms
Physically checked trigger points tested trigger points
I did a "smoke" test. I pulled the vacuum line off of the Pressure sensor, and blew smoke into the intake. I did get a little bit coming out from the 90 degree elbow, but surely not enough to prevent the car from running.

I'm starting to thing it's ignition, even though I get a spark, I think I have a problem there. Reason being, after cranking, the car sputters and stalls, after the engine stops spinning, I turn the key to "Off" position, and I get a little kick in the engine, as if I'm only getting a spark while cranking and when I turn the car off.

The plugs in the car are RN9YC, and the rotor looks like it's got a resistor built in to it as well. Could it be to much resistance in the spark plug path?
Oh and yesterday I poured a little gas down the throat with no difference in cranking/sputtering.

Have you measured the dwell signal at the points? 30 deg.

Also have you replaced OR cleaned the points?

I measured dwell, one time when the car ran for a few seconds, and it was at 30. I cleaned the points (they were blue)