I have a 91 z-28 ran fine then one day started to missfire and shut off.The next day started up ran 10 minutes or so then shut off.Has fuel spark but lost injector pulse.Power at the injectors but no ground.I have replaced computer with dealer one.dist,coil,cap,rotor,plugs,wires,oil pressswitch.Everything has been replaced more than once and still has the same problem.Took it to a shop and nothing shows up on a scan tool.They said computer but im on my fourth one now and its getting expensive.Im lost any body have any ideas?

 

Both injector banks or just one?
Ohm test the injectors. One bad ( grounded ) injector will cause the ECM to shut the whole bank down

 

Both banks. Now the car will only start on starting fluid.Still has fuel at the rail and spark but no pulse.The longer the car ran the worse it would run then just shut off.The way I got it to start last time was by unplugging the injectors one by one then plugged them back in and it fired up.Had a missfire like lack off fuel but it did run.

 

Wonder if the security system could be causing this? VATs module sends a pulsing ground to the ECM allowing the injectors to fire. Don't know if a fault in this would cause the engine to shut down once it's running though.

 

My 92 Formula is doin the exact same thing. I managed to tap into the low side for bank one and tap the ground a few time to pre-prime the injectors. After that it starts up and runs rough but still continues running for a while. I also pulled the vacuum line off for the fuel pressure regulator and it actually ran better...

 

This.

 

the ECM only has 1 driver in it for the injectors. so both banks won't fire if the ECM is damaged because of a bad injector.
like was said, check the resistance of the injectors.
once its running, the VATS won't cause it to die. it just won't start and run for more than 2 seconds if there is a VATS problem.

87CamaroLT43, my car has done the same thing to me twice.
the first time it died a few times while driving and then refused to start back up.
it decided to start and run while i was trouble shooting it, so i didn't really have a chance to narrow the problem down.
the second time it acted up, i found low voltage at the ECM. as soon as i put a battery charger on it, it fired right up.
the battery was a little low, so im still not certain of what the problem is.
i've had problems with the ignition switch causing a no start in the past. but that switch was around 20 years old, the one in it now is only about 5 years old. but Delco may very well have cheaped out on the contacts in the ignition switches now.
i really hate having to wait for it to act up again, knowing its going to die and not restart at some time makes me not want to drive it.