Hierarchy of likely fuel injection faults

Disconnect the ECU

Ground pin 20, then pin 21 of the ECU

• Pump doesn't run?   Either or both relays is/are bad; stop and repair
• Pump runs? Pump relay is OK; proceed

Remove ground from pin 20; leave pin 21 grounded, then ground pin 18

• Fuel injectors do not click?  Fuel System relay is bad, or corrosion in the large round connector; stop and repair.
• Fuel injectors click?  Proceed
  • Check for voltage on pin 5 of the air mass meter connector
    •  No voltage?  System relay is bad;  stop and repair.
    •  Voltage OK?  System relay is OK: proceed

•  If YES TO ALL, the fuel system is working well enough that the engine should at least start  (although the Air Mass Meter could be bad).
  • If no voltage, no injector clicks and pump does not run, then something is probably wrong in the crank sensor circuit.
  • If only the pump runs or only the injectors show voltage and click, suspect the ECU.
    • NOTE: ECU failures are NOT common; the problem is almost always something simpler, such as a relay, or corrosion.

AND A FINAL NOTE: I once read voltage over and over and over again at the injectors - the voltage was there, but corrosion in the round connector prevented any significant current from flowing.  SO be sure that you have current as well as voltage - make sure the injectors click.  They may be hard to distinguish when the engine is running or cranking, but you should definitely hear them in the pin 18 test.