Need help please. Strange no start

[jbs3]

Just got my engine back in after replacing blown airbox and a bunch of other stuff. When trying to start it cranked but would not start. Checked the standard stuff. Have spark, have compression, pressure readings as follows:

System pressure: 4.5
Control pressure @ 32 degrees: 3.4
Residual pressure after 15 min : 1.6

I pulled #4 injector, put into glass jar, to see if fuel was flowing with key in on position and sensor plate lifted, it was. I then tried starting the car with the injector still in the jar. The car started and was running, not well but it was running.

Let it run for a while and turned it off, put the injector back in the engine and tried to start it again, no go. Took the injector out again and the engine started up. Put it back in and No Start.

Other than trying to fix this with my meager skills, what could be going on to explain this. I need help.

[jbs3]

Sorry. Its a standard 81sc. Upgraded fuse panel, 123 ignition distributor, new airbox, new fuel pump.

[blucille]

just curious, when you put the injector back in and tried to start it, did you lift the sensor plate?

[SkiVT]

Do you have this already? Pressures seem a bit off.

[jbs3]

Yes i lifted the sensor plate and the pump turned on.