1989 Firebird won't start

[DarkThunder]

I recently had to do a rebuild of my 2.8 engine. All seemed to go fine except now it won't start.
I replaced the plugs, wires, coil, rotor, and distributor cap.
Here are the symptoms:

-Turns over fine

-Spark is fine

-Timing is set correctly per a professional machine

-I can hear the fuel pump

-When I pop the schraeder vavle on the fuel rail there is fuel with pressure behind it

-The spark plugs are wet with fuel

-I have performed continuity checks on the wiring from the various engine components to the ECM connectors with no help.

-The ECM was working fine before the rebuild and the battery has been disconnected during the work

- The vehicle code listed was 21 for the throttle position indicator, none other than that

- Additionally I have found that if I take back apart the fuel system and drain the feul from the rail, right after I reassemble everything, it will try to start for a short time. Not successfully, as if it cannot get enough [COLOR=green! important][COLOR=green! important]gas[/color][/color], but then after a while it will not try anymore and will just turn over.

[wrightz28]

That TPS reference volt problem will do this.