I've got a 90 grand prix that is set up for the dirt track. It up and died and won't run. It fires, then dies. It will run on starting fluid. There is 30+psi fuel pressure at the rail. I checked one injector with the noid tester and it starts out fairly bright and then gets dimmer until there is nothing. You have to take off the manifold to test the rest. I replaced the ECM with no change. I checked for trouble codes and only got one, 12 which means there isn't anything wrong. I went through and checked all the grounds and cleaned them up.
HELP!!