Just replaced fuel pressure regulator. Have 40 PSI when I turn key to on. Car tries to fire but won't start. Runs with starting fluid just fine. I'm not sure where to go next. It would be great if anyone has some input.

I replaced the regulator, because it was likely the factory one was bad, I think it was leaking past the diaphragm into the vacuum line as the car ran rich and would not idle, but ran great when accelerating.

 

I’m assuming you have tpi or maybe 3.1L ?
Have you checked for spark and injector pulse with a noid light ?

 

Crap, the engine would be helpful wouldn't it. It's a 92 L98 TPI car.

 

I do have spark, because if will fire with starting fluid, but have not checked injector pulse, will try that next. Thanks!

 

Check for injector pulse, also pull check engine codes.
This could be a vats issue. Checking to see key on if you have voltage from the passkey module to the ecm.
This is a hz signal but you can see 2.5v if it’s working. Pin f10 a blue wire at the ecm.
The icm could be faulty as well. You can have spark without a reference voltage.