First time to the board folks, so forgive any lack of decorum. Recently tracked down a long lost friend...a 1988 Firebird Formula 5.0! Lots of work to be done, but checking things off the list one at a time. Here's where I'm at. When I turn the key to the ON position, the TBI injectors "pulse" an initial shot of fuel. It's my understanding the injector should continue to pulse fuel as the vehicle is started, but this isn't happening. LED light testing shows power getting to the TBI wires. Noid light illuminates, but doesn't pulse when engine is started. Just to be sure, tested each of the injectors using 9V battery on start up and the injectors continuously pulse. Suggest problem isn't the injectors. Not sure where to go from here. Replace TBI wiring harness, maybe? Any insight is appreciated.

 

Check for spark during cranking, if it goes away fix that first. The ECM requires distributor reference pulses (DRPs) in order to fire the injectors.

RBob.

 

Injectors are powered when key is "on", ECM switches ground to make them pulse.

As said, no spark, no injector pulse is typically a problem "in" the distributor--pickup coil, or (less likely) the ignition module.

'Course, as with all electrical failures, it won't hurt to verify all the fuses, and that the battery has 12.6--12.7 volts with no load.