I'm trying to resurrect my 91 caprice. It will start and run as long as I am using ether or carb cleaner. I have already replaced the fuel pump about 6 months before it died. Other than checking the fuel pump relay and the pump itself, what else should I check? Is the TBI system controlled by the computer?

Thanks

 

check the fuel filter and fuel pressure,
with the TBI you may be able to see the injector squirting fuel into the throttle body when cranking, if you see it drip or dribble the injector is blocked or clogged or fuel pressure is too little, it should produce a nice cone shape if working correctly..