May be the wrong pressure on the fuel pump or the new fuel pressure reg. is defective.
Thanks for not listing which engine you have---as if they're all the same.
But check out the engine coolant temp sensor first. If that's not right on, you'll get either a rich or lean mixture.
That E85 you've been running in it has ruined to whole fuel system.
E85?
It's cranking great, has got spark, timings on, and new fuel regulator.
