I have 1994 4.9 that will not fire.what would cause this? on 1994 Cadillac DeVille

it has a new distributor-coil-good fuel pressure-no engine codes-used the second key-been in 2 shops-new module-cam shaft sensor-still no fire.

did you check to see if you have injector pulse?
one shop says he got it started--with starter fluid-but did not have injector pulse.
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If any chance did you replace the igniter module?
have it scan tested to check the cts {coolant temp sensor} you will need a tech11 scanner so you can get data stream as well as any codes