It depends on the type of injection system. Look at the ground wires by the distributor. I just repaired a blazer that was doing the same thing and the black/white wire that is a ground for the distributor and for the fuel injection was cracked. I replaced the broken wire and it quit flooding and ran fine. These vehicles get thier fuel pulse signal from the pick-up coil in the distributor and if it is damaged they tend to flood out or not get any fuel at all.