I just installed new fuel pump 3 days ago. car has ran OK since then for short runs. Car died while traveling down the road at 55mph after traveling 5 miles from home. Just cut off. No skipping or jerking. Just turned off. Will not start up and go again. I got it to start again but will not stay running for more than a few seconds. I filled it up with gas. I have had a new MSD coil on it for 4 months now. New plugs/wires. Gonna check fuel pressure in case I got a bad Walbro pump.
I'm wondering if a FuelPressureRegulator can cause problem like this? How to check FPR? What else could I look for? Battery is good. Starter turning fine.

 

with the key on and engine off you should see 41PSI +/- about 2 and it should hold there. that should be enough to get you to have it started. when it starts it should drop anywhere from 2-8PSI range with full vacuum. with it running and the vacuum line ff it shold read back to 41

 

Simple check for the FPR is to pull the vaccuum line after the system has been pressurized. If fuel comes out of it, you need a new one.

FWIW, if a motor dies from a fuel starvation issuse, it won't just immediately die. It would shudder and hesitate, and then die out. I just went through this not too long ago myself in fact.