Nissan Pick-ups and Pathfinder 1970-1988

Fuel Injected Engines


The Electronic Concentrated engine Control System (ECCS) is used on these engines. This system employs a microcomputer which controls fuel injection, spark timing, Exhaust Gas Recirculation (EGR), idle speed, fuel pump operation and mixture ratio feedback. Electrical signals from each sensor are fed into the computer and each actuator is controlled by an electrical pulse with a duration that is computed in the microcomputer. There are some basic tests that may be performed to check the ignition system as outlined under Troubleshooting later in this section, however, when engine malfunctions occur, the use of an ECCS analyzer is necessary to accurately diagnose the problem.

The ECCS analyzer monitors several input and output signals that are emitted in response to various engine operating and stopped conditions. Input signals are compared to computerized signal values stored in the Central Electronic Control Unit (CECU) while output signals are monitored to ensure they are properly attuned before they are emitted from the CECU unit to the actuators. In other words, this analyzer examines all electrical signals that are transmitted to and from the CECU unit.

Since this analyzer would be very expensive to purchase, any suspected malfunction of the engine cannot be corrected by an obvious visual inspection, that should be left to a qualified repair shop that contains this equipment.