My car will not start intermittently. Fuel pump ok and turns over. on 2007 Ford Taurus

Diagnostic computer says there is no problem. Replaced battery just to make sure not power problem. 3 mechanics have not been able to figure out including dealership. Friend suggested relay for fuel pump? Once it is running it runs great.

2 answers 1 comment
Have mechanic check for fuel pressure bleed off after engine is switched off, should hold pressure.
does car turn over but not start? or does it do nothing?
The car does turn over but doesn't start.