99 s10 blazer. turn key on. dash lights come on for bulb check. Security light on solid for approx 3 secs then goes out. hear the fuel pump come on for approx 2 secs. starts right up and then dies in about a second. dash lights come back on security light comes on for about a second. Then blinks one time and goes out. If I add gas directly into the throttle body it keeps running until I quit adding. The fuel injecters are not firing. Is this a passlock problem or a sensor not reading correctly. If a sensor problem any ideas about which one. Thanks for any help.

 

What size is the engine?

 

Its a 4.3 vortec V6. The only engine offered on the 99 S10 Blazer