1995 GMC c1500 Sierra 5.7l crank no start
 

I have a 1995 1500 sierra 5.7l crank no start situation. Starting has been getting harder and harder over the last month.
Finally gave it up.
Here is the work record over the last few months- to a year.
- new fuel pump
- new starter
- new plugs
- tbi rebuild kit
- new egr valve
- new battery
Also recent work done on it,
- spark on all cylinders
- fuel at tbi
- spark plug resistance ok on all wires
Are there any sensors that would prevent a start?
Suggestions?
Thanks