LJetronic EFI Analyzers


Miller Tool Co. Nissan/Datsun Electronic Fuel Injection Analyzer

Model MST 4802

Electronic Fuel Injection Analyzer, Model MST 4802, is a universal tester for the use on all “L-Jetronic” type electronic fuel injector system installed on Nissan/Datsun vehicles imported into the U.S.A. since 1975, except those equipped with the E.C.C.S./Turbo System. Using the MST 4802 Analyzer, you can diagnose the electrical side of the EFI system, including sensors, voltage inputs, injectors and all related wiring and connection leading to and from the Electronic Control Unit (ECU). The analyzer incorporates a separate LED to test each individual EFI circuit for continuity, along with an LED Ohm/Temperature meter to test for correct resistance in the air flow meter, the coolant or cylinder head temperature sensors and the intake temperature sensor.

 

 


Bosch system. More info here.

 


Ditron 811L

This tester substitutes for the ECU and does not test any functionality of the ECU. The manual also includes procedures for adjusting the air flow meter.

  1. Battery voltage
  2. Air temperature sensor
  3. Engine temperature sensor
  4. Fuel injector pressure drop test (looks for clogged/mismatched injectors)
  5. Air flow meter test (running test) - as with the 812D, the unit has a built-in subset of the ECU circuits so that the car can run with the tester attached. Permits monitoring of the air vane under running conditions, with specific meter ranges for various conditions. Also has mixture control, potentially could be used for performance tuning.
  6. O2 sensor ('79 Datsun only) - qualitative testing of O2 sensor functionality
  7. Ground test (verifies ground wires are connected)
  8. Throttle switch test

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