express van wont start

Just replaced fuel pressure regulator, will run if brake cleaner is sprayed in air intake.

I'd check the fuel pressure and the wiring to the fuel pump.

Welcome to AF.
What year and engine?
Cutway or regular?
Does fuel pump run?
If so what is the pressure?
If not.
Check for power in the fuse boxes.
Check for 12 volts power to fuel pump relay and for 12 volts to fuel pump gray wire.