turns over and fires but won't run

I have an 86 corvette coupe it turns over and fires but won't run the vats has been bypassed it has 40 lbs at the injectors but won't run it tries to start what could be the problem

I've also bypassed the vats it has 40 lbs at the injectors but drops when you stop cranking the engine.it also tries to start. if i spray starting fluid in the intake it will but won't stay running