Pontiac Repair: No fuel Injection, pontiac sunbird, car mechanic

Question
My car, 91 Pontiac Sunbird LE, 4 cyl, auto, normally runs great.  My fuel injector does not spray and car won't start. I replaced the MAP sensor (due to error code) and the car started immediately for only 2 days. I have no error codes now. I replaced the oxygen sensor (error code) and installed a new fuel injector (FI) today (last resort?).  I have 12 volts going to the FI,and the fuel pump works fine. But no fuel spraying!  The 3 large relays on firewall work fine (AC, fuel, and ?). Please help - I am not a car mechanic. Thank you.  

Answer
Hi
There are a few things you could check.
Is the car firing?  If NOT you may have a faulty ignition control module inside the distributor. That is where the ECM recieves the reference for the fuel shot.
You could check the wire from the ECM to the Fuel injector (Dark Blue). Make sure it is good. If so,
the ONLY other item I see in that system is the ECM.
You may want to take it to a repair shop and have them check all realted wiring.
I hope this helps.
Just advice from experience.
Good Luck
Paul