new engine won't start
 

I have just installed a 2.3l rebuild. It started and ran for about 3 minutes. I could not throttle it up, it would just sound like it was bogging down, then die. Then it would not start up again. It trys to start, but won't. I sprayed starter fluid into the baffle area after the MAF, and it started right up and ran till it ran out of S/F. Checked Fuel pressure without guage, by pushing down on shrader valve. Very little gas comes out. Seems to be lack of fuel from pump. I can hear pump run win key is on, for about 2-3 seconds. But very little fuel.
I don't want to replace F/P unless I know for certain that's what it is.
Any Help would be appreciated.
Also truck has been sitting for about 18 months.
1995 2.3l Ford Ranger XLT 2WD Extended Cab
Thanks, Ed

'95 will have the lower pressure system with return fuel line.
Should have about 45psi at the fuel rail.

Fuel pressure is maintained by the FPR(fuel pressure regulator) on the fuel rail, it has a vacuum line attached.
Inside the FPR is a rubber diaphragm and a spring to hold it closed, this maintains fuel pressure, when engine starts the vacuum in the intake pulls open the diaphragm a bit allowing fuel to flow back to the tank at idle, as RPMs increase and vacuum is less, so more fuel stays in the rail.

There is also a check valve on the fuel pump, so fuel can flow out of the tank but not back in on that line.

These two things hold fuel pressure at the rail when engine is off, and also maintain pressure when engine is running.

I would cycle the key on and off a few times, that is normal for the fuel pump to run only 2 seconds each time key is turned on, so count to 3 with key on then turn it off and on again.

Test the pressure at the rail, then cycle key on and off a few more times and wait for 5 minutes and then test the pressure, if there is little to no pressure then either the FPR is not working or the check valve isn't.