low res pulse only between 1 and 2 volts ac when read from pin b of icm harness

no I have no clue which pulse I am looking at I just know which wire I'm hooking the scope up to. I know how the opti works as far as the discs with different size holes and that the sensor gets one signal from the slots and the other from the holes that are sized different for the other signal. I know nothing about the scope I was under the assumption that if I hooked it up to that wire it would get the signal that I wanted to look at. I have tried to look for videos or even write ups that explain what I need to look for with this engine when using a scope but so far I haven't found anything that is specific enough to help. I'm guessing that the opti got condensation in it so has enough corrosion that it is disturbing the signal enough to make it run poorly but still run, but that's why I wanted to look at the signals with the scope so I could say with more certainty what is going wrong. If it is the opti I am just going to save up and get the 24x conversion so I don't have to worry about all the issues especially with the un vented version, but its a lot of money to spend if my current problem is not in the opti. since it is still in the car I was hoping I would find more videos and things with people using them on the lt1 so I could learn more about what I need to look for and if there is a different place I am supposed to hook the scope up other than the pin b wire at the ICM because that is where everything I have found so far says to connect the scope to, but since I haven't seen anybody use one on an lt1 engine, except one video but they were in too much light so I couldn't see the screen on the scope they had or where it was connected, I don't know what to look for from the test other than clean square waves, the test I did had squarish waves but they were very distorted at times with extra lines and things like that but they did get closer together and everything when I increased the rpm but I couldn't get pics of that since I was short on hands all the pics are during idle.

I am having trouble getting this test to work properly, the first time I tried last night I got a reading but by the time I got out of the car to look at the screen then pull out my phone to take some pics it killed the car. I also accidentally had it set to 1 volt or something so all that the screen would show was lines rather than a wave that was readable but it was set to 500ms so that part was correct then today when I tried again every time I had the scope hooked up the car wouldn't start, it was set to 10 volts this time. It would start right up when I disconnected the scope every time and I tried it about 5 times. Is there a reason it would either kill the car or make it so the car just wouldn't start when the scope was hooked up, it was connected to the low res signal wire and I am pretty confidant I had a good ground because I ran a 6 gauge wire bolted to the grounding block on the passenger fender area. The wires for the probes aren't that long so this allowed me to get the scope closer to where I needed it and still have a good ground.

There is ABSOLUTELY no reason for the scope to kill the car, UNLESS you have a problem with the wire going from the pulse to the scope. Something like its insulation is burnt and it's grounding.

Or if something in the scope died. Put your meter on Ohms and check the scope. Meter leads to scope leads. It should read very high Ohms and the scope's zero line should jump up indicating a voltage. You can also set the scope on 5 Volts per division and read the battery voltage, it should be very close to what your meter reads.

About Ohms, a direct short should read zero Ohms. That's touching the leads together. Nothing is impeding the flow of electricity. If you measure your resistance, one lead pinched in the fingers of each hand, you'll see high resistance. Your body is "resisting" the flow of electricity.

You had the scope set to one Volt a division, that's what it should be set at. 500 MS is 1/2 second per division. That seems to me to be a good starting point. You can adjust that when you get it working. I would expect to be at around 50 MS.

One thing you don't want to do is connect the scope to the ANY spark coil leads. That's a no-no. If you want to see what's going on at the coil's primary leads, ask me and I'll tell you how.

You're doing well. Just having teething problems.

Al in Tucson

The meter I have is an "astroAi' brand 6000 count amazon buy, I think it was like 40 or 50 bucks so nothing special and from what is on the shoebox page I did that test right but its more of a test to see if the opti is pulsing but I think its a better test for a car that is a no start just to see if the opti is sending the signal through the pcm to the coil but wont diagnose any problems just a working or not kind of thing, but at the time I wasn't sure if the meter should have varied more in voltage while turning the car over but now I know a normal meter cant read fast enough to diagnose those things. I thought i was supposed to use the scope at the same spot as that but from what i understand the only way to look at the signals both low and high is between the opti and pcm with a scope not after the pcm has looked at the signals and sends the info to the icm and coil. I just got another break from things here so i havnt used the meter to check out how things are working with the scope but i will get that checked tonight. Thanks for the help im still learning the electronic side of these cars so its been a slow process.