I have a 1999 F150 4.2L. Can someone tell me what the signs and symptoms are for a bad pressure regulator?

 

Only way to tell anything is test fuel pressure with a gage on the test port.
Engine at idle 30 to 45 psi.
Remove the vacuum hose, read 40 to 50 psi.
Engine shut down after test should hold pressure for 5 min at 30 to 40 psi.
.
Issues caused by too high or too low pressure are many and varied from rich running to lean fuel starvation.
These conditions set a number of codes depending on what and when the systerm detected an issue via the OX sensors.
A low pressure can be a faulty fuel pump or a plugged filter.
Long crank times could be the fuel pump.
I can't answer only to you general question so what problem are you having?
Good luck.

 

No codes Bluegrass. Every once in a while it lacks power and will shutter or have a slight miss on take off. Idles rough at times. No vac leaks. Throttle body is clean as a whistle and new IAC valve. New plugs and wires were installed just about an hour ago. I haven't test drove it yet but it seems to idle better. I thought maybe a plug or wire was breaking down under a load. I also changed the coil pack.

 

If the regulator fails, gas leaks back to the tank and you have starting problems / lag. THe pressure should be maintained on the fuel rail for several hours. Put a gauge on the schrader valve, or just push the center pin after a few hours and see if pressure is good.

 

I have to turn key on for 2 mins before cranking so truck will start 2001 f 150 v8.