The injector ground signals are directly wired into the ecu, unplug the ecu connectors and check the ecu connector pins with the other end of the multimeter at the injector pins. They should have a connection ( almost no resistance). If you don't have that, the loom is hacked up somewhere. Since you got power to the injectors, it's not a fuse or MFI relay issue.
The ecu gives the signal to fire the injectors already when in cranking mode (starter signal to ecu).
Even without a cam/cas signal during that time.
If the wire loom does check out it's an issue with the ecu (ecm) probably.
You can unhook TPS, maf and cam /cas and ptu, fuelpump, but the injectors should get a pulse to work in crank mode independently.
If the ecu does not see a good cam /cas signal it will shut down. Once you let go of the starter.
If no fuel enters but you got spark your fluid you just sprayed will ignite once or so, that explains the short 'running'.
Last edited by enkaio; 04-09-2019 at 08:35 AM.