You just replaced the fuel pump in your 1989 gmc k1500 with a 5.7 tbi It get fuel up to the throttle body And it still wont start what else could be wrong?

Answer

Is the injector actually jetting fuel into the throttle body? Ifnot the injector could be fouled. Make sure you have spark from the plugs. If not check the coil\distributor. if that doesnt work, make sure the vehicle is not backfiring because that is caused by a bad timing.. check your injector a+b fuse, and check the wiring running to the injectors...