When I try to start the car now it turns over well but will not start as of last night.

Summary of events so far:
3 weeks ago car started running poorly and stalling. It gave me a cam sensor and crank sensor code.

I changed both sensors twice.

Still ran bad and kicked the same codes after I cleared them and drove the car.

I checked the fuel presure twice both times around 60psi

I tested the ignition system at the icm connector as stated in this link.
https://easyautodiagnostics.com/gm/3.8L/ignition-module-and-crank-sensor-test-1

I also found and removed the wire that grounds the system to the engine. Cleaned both sides with a wire brush and reattached.

Cleaned the connector to the ICM w a wire brush

I thought i fixed it at this point bc the car started and ran well. It appeared the tachometer stoped jumping and the car wasnt stalling anymore. I drove the car around my sub for 30 minutes and all appeared good. For ths first time I didnt get the crank and cam sensor codes anymore. Parked it and tried to start it the next day and it cranked but didnt start.

Checked spark at the coil seen none. (I did have spark previously)

I tested the ignition system at the icm connector as stated in this link.

https://easyautodiagnostics.com/gm/3.8L/ignition-module-and-crank-sensor-test-1

If i interpeeted the test right it seemed like the ICM may be going bad which made sense to me since it seemed like I was getting spark sometimes and not others and the previous issues and P codes.

While I was running the test maybe test 4 or 5 the car started so i had spark again out of nowhere.

I went on vacation and when i got home i sarted it up seemed to run fine pulled it in the garage and replaced the ICM.

I replaced the ICM with a new acdelco part from rock auto, and I thought it would be golden and i havent gotten spark since. I tried to start it about 20 times and nothing. I feel like its worse now that i put the new ICM in it but I dont know how that could be possible. Did I do something wrong? What else can I be missing? Is it possibly the connector to the ICM and everytime I mess with it or jostle it things change it either starts working or stops?

I have been working on this for a few weeks and am getting ready frsutrated. Any new thoughts or ideas are appreciated.

Sounds like the connector and or it'* wiring has a problem.

BTW....make sure there is no green death (corrosion) on the connectors.

What do you mean by green death on the connectors? Just like srandard greenish corrosion? If so there was definitely some of that. I tried to clean ki t with a wire brush.

You need to clean them COMPLETELY or replace the connector. See if you can find a spray that neutralizes the acid. I've had some success in making a solution using baking soda and water. and soak the connector in it. Use a toothbrush and scrub it. Use plenty of soda and if it quits fizzing and there'* still green death on it make a fresh batch and keep it up until it'* COMPLETELY clean. Blow dry and use dielectric grease and install.

What carfixer007 said ^^^^^

. . . and: Have you checked the condition of the wiring from the crank and cam sensors to verify condition? Those wires are in a pretty hostile area once they turn downward from above.

Well first thing I would do is get a male pin from a GM dealership parts department that is the same pin size as the ICM......use it to do a "drag" test, on every female connector in the ICM harness......if the pin does not drag out after inserting, the female connector is loose, and can cause intermittent problems, and possibly arcing(thus the connector must be replaced in the harness)......Do the drag test on the harness to the crank sensor.....should be same male pin......the cam sensor is not needed for spark.......

I assume you have tested the signals from the crank sensor to the ICM? Have you checked all power and grounds to the ICM?

This is similar to a tool I use for probing circuits:

Thanks @tech2 . I ordered very similar probes to the ones in thr link. They made things so much easier. My issue was more Im not 100% sure if I did the tests right or interpreted rhe results right.

https://easyautodiagnostics.com/gm/3...-sensor-test-5

Above was the link I dollowed when testing. 8 tested power ground and they were clearly good. Power and ground were both between 10 and 12 v. Crank sensor was also getting a power. I rhink the 18x xkp sensor was good the led inused blinked as stated in the link i found. I was a little concerned about the 3x ckp test bc at first i tried it and i disnt get any light but inwent back and tried again i belive it gave me a constant light. After i tested that the car magical started right up and ran well. Its almost like i get didderent results the more i mess with the icm wires. When i get home i will retest rhem again.

@CathedralCub im not sure I would know what to look for whwn looking at the wires. From what i could tell the cam and crank sensors and wires looked good. I didnt see any nicks or corosion. Alot of the wires run up into areas i really cant see though.

@carfixer007 Thanks I will try that when I get home since a new connector is like 80 bucks whxih seems crazy for a connector.