Gmc 4.3l

i have a 1992 gmc 1500 4.3l i bought the truck not running after going trough motor and replacing head gaskets pistons and several other parts finally got ready to start it seems to be getting to much fuel and will not start so i unplug one injector and it starts right up any suggestions on what my next step should be are appriciated

There may be a problem with the fuel meter body of the throttle body injection system. http://www.autozone.com/shopping/repairGuide.htm?pageId=0900c1528008f1fa

Tester

Have you checked the fuel pressure to see whether it is within specs? And also check the fuel pressure regulator - pull its vac hose & look for fuel as it may be leaking & sending extra fuel into the intake.

should i pull the throttle body and have it checked or is it possible that the computer has it in choke mode and pumping more fuel

if the regulator leaks would the fuel go through the injector or straight into the intake

Depending on how it fails (if this has anything to do with it), it can result in too much pressure to the injectors (regulator stuck closed, not providing return to tank), or to fuel going into the intake (leaky diaphragm), or perhaps both.