I am just finishing up replacing a set of injectors in my 89 IROC (5.0/TPI). I did this based on the car running rough (missing...like it was starved for fuel). Prior to this, I replaced the Mass Airflow Sensor, installed a rebuilt distributor, tuned/timed (fuel filter, plugs, wires, coil).
I did the injector swap following directions from a tech article on this site https://www.thirdgen.org/injectorswap (good article...very helpful). I have installed the runners and decided to check for fuel leaks before I installed the plenums. I put a fuel pressure guage on, connected the battery and turned the ignition on...nothing..no fuel pressure. I disconnected the fuel supply, then the return lines then tried again and a low trickle of fuel flows from the supply line. Are there any switches/lines, etc that have to be connected on intake system for the fuel pump to work? I still haven't reconnected most of the wires/connections I took off for the swap.
I have heard that there is some sort of fuel return line in the fuel tank and that if it is leaking fuel will return back into the tank and thereby...no fuel pressure. By the way, I also had the fuel pump replaced (when I did the tune up).
Has anyone encountered this problem. Assuming that the fuel pump is good, where do I start?
I am really considering swapping this over to a carb system but am unsure of the emissions implications in the state I live in CT...recently moved here from California and haven't registered the car yet.
Any advice is appreciated.
Thanks

 

It should have FP. Are the injectors plugged in? Don't dump the TPI, it's much better than a carb when it's working. Did the gauge your using register FP before the swap? Do you hear the pump run for a second when you turn the key?

 

Check the Fuel Pump fuse over by the battery. Is the pump coming on?

 

ARE YOU SURE YOU HAVE THE PRESSURE LINE ON THE INLET SIDE OF THE RAIL. IF YOU TRY TO PUT PRESSURE TO THE WRONG SIDE IT WON'T WORK.

 

The injectors are plugged in. I don't believe that the pump is coming on...don't hear anything when I turn the key on. The car ran (rough) before I pulled the injectors/TPI system off though, so I had to have some pressure? Yes, I am begining to believe that the whole issue was fuel pressure from the begining....maybe didn't need to replace the injectors.
There are 2 relays above the battery. One is on the passenger fender side and one is towards the front of the car? Are either of these two the fuel pump relay? Is there also a fuse to check?

 

If it's the same as my '87, the fuse is beside the battery (by itself, in-line) and it's the relay in the middle by the brake booster.