if those little fins are bent thats not going to work properly, thats what tells the icm/pcm when to spark. if you have pulses missing seems like a good thing to check.

just got balancer off. the 3x fins were fine. one of the 18x was bent and definitely not going thru sensor. still had shreds of serpentine belt still wrapped around also. crank sensor looks fine but at this point i will pick up new one tomorrow.

Sounds like that could be the problem, let us know how it goes when you get it replaced, replacing the crank sensor even though it may not be bad is a good idea, as they are known to become problematic, I replaced mine back in 2012 even though it was still good, I had access to the area at the time, and I figured why not.
I hope a new balancer and CKP fix the issue!

Having that spare new ICM is not a bad thing either, they are known to have issues as well, as I am sure you have read up on, I have me a spare one put up just in case I ever need it.

i just bent that one tab back in place. real easy to bend but they are relatively safe from danger except an occasional serpentine belt. anyway it is back running. my old icm is probably good but i would say it was a logical step in troubleshooting to replace it. 3 months ago i had to replace the plenum where the egr tube melted the plastic and filled intake and cylinders with water. i hope shes ready to run a few more years now. thanks for the help. hope to return favor one day

Glad to hear you were able to bend the tab back, and get it to run well, thanks for letting us know the outcome.

I wish I had thought to tell you to examine the balancer and crank sensor wiring before you had to buy the ICM, but it is good to have that new one, if anything put the new one on, and hold on to the old one as a spare for possible future troubleshooting.

When you replaced your plenum did you replace the LIM gasket as well, they are known to fail, they have an aluminum framed gasket that I recommend replacing the old plastic one with, unless you already replaced that old one with the aluminum framed one.
Also the upper intake manifold kit should have had a reduced diameter EGR Stovepipe, I hope you replaced the old one with that, it helps solve the problem you mentioned from the EGR gasses.

yes, plenum came as complete kit with all gaskets and updated egr piping

Good deal then, did you also get and replace the Lower Intake Manifold Gasket as well?
I assume you did, but asking to be sure, as it can fail and let coolant into your cylinders, which can possibly destroy your motor.

Here is the one I recommend, of course the AC Delco one that is also aluminum framed is acceptable as well.