riviera turning over but not getting any spark from module

I changed the ignition module, crank sensor, ECM and plugs but there is no spark coming from the module please help if you can...Thanks!!!

Check all the ground wires. There is one that comes off the Ignition Control Unit and is bolted to the block under the ICM. That one gets broken easily or just corroded.
Remove the coil packs from the ICM and check the condition of the bottoms of them for corrosion, clean with scotchbrite pad or emery paper. Also pull the ICM again and check the underside and top of it for corrosion, same thing there, clean all corrosion and put a light film of dielectric grease on the mating surfaces. All those components need a clean path to ground.

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98 Riv, 102K Miles, EBC, LS1 Ft.Calipers, STB, Addco Rr Sway Bar, 180* stat., SSAC Headers, HF Cat, 1.9's,
105# springs, MPS 3.4, DHP tuned by the Deekster.

another thing after i changed the PCM it stumbles the entire time it is cranked and the only way it stays cranked is if i hold the gas down (still sounds real rough and you can tell its not getting any gas)

what do you mean 'stays cranked'? Will it start, but run very rough? Or are you holding the starter (cranking)? Please elaborate.

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'98 Buick Riviera; Gen V 3.25 pulley, N*, VS Cam, 180 stat, Custom PCM (Powrtuner), headers & HF cat , 42.5 lb inj.

Grant-built/PRJ/Thrasher trans 3.29 gears, 7/8 chain, zzp hardened IS

Also, will it not even crank (starter rotating) unless you have the gas pedal pushed to the floor.?
What happens if you lift your foot off the gas pedal while the key is turned to the start position and starter is cranking?
Does it just stop cranking as if you turned the key off.?

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98 Riv, 102K Miles, EBC, LS1 Ft.Calipers, STB, Addco Rr Sway Bar, 180* stat., SSAC Headers, HF Cat, 1.9's,
105# springs, MPS 3.4, DHP tuned by the Deekster.