Description

Nissan D-21 Technical Manual – Fuel & Emission Control for the Hardbody

If you have been chasing an idle problem on a D-21 Hardbody and ended up with a generic manual that tells you to “check the sensor” without telling you which pin to probe, I know the frustration. Aftermarket manuals skip the fine print. This Nissan D-21 Technical Manual is a genuine factory document — 155 pages of Spanish-language technical data that covers the fuel and emission control system from the pump to the evaporative canister. No translation errors, no guesswork. You get the same procedures the dealer techs used. Page references are based on the original section numbering (SC y CE).

Fuel System Inspection: SC y CE-150 Coverage

The section INSPECCION DEL SISTEMA DE CONTROL DE INYECCION DE COMBUSTIBLE (page SC y CE-150) walks through the injector circuit, fuel pressure regulator check, and harness continuity tests. It tells you exactly which special service tool (EG11180000) to use for engine speed measurement. No third-party interpretations — just Nissan’s own steps.

Idle Speed Check and Ignition Timing – Factory Specs Inside

Section COMPROBACION DE LA VELOCIDAD EN RALENTI/AJUSTE DEL TIEMPO DE ENCENDIDO/RELACION DE MEZCLA EN RALENTI (page SC y CE-26) gives the factory procedure for setting base idle and timing. If you have ever had a D-21 fail a smog check because the mixture was off, this is the page you need. It lists the correct idle mixture adjustment sequence — something aftermarket books often omit.

3 Safety Warnings Before You Start

The manual’s PRECAUCIONES section (page SC y CE-3) is worth reading twice. It warns against operating the fuel pump with an empty tank, never spraying battery electrolyte directly on injectors, and not applying detergents to the airflow sensor. One of the most overlooked warnings: No golpée o deje caer el sensor de oxigeno — dropping the oxygen sensor can ruin it. Those details keep you from buying parts you didn’t need to replace.

Does This Manual Cover the Evaporative Emission System?

Yes. The chapter SISTEMA DE CONTROL DE EMISIONES EVAPORATIVAS starts on SC y CE-153 and runs to SC y CE-155. It includes the charcoal canister purge test, line routing, and the vacuum switch check. For a 20-year-old Hardbody, that is the difference between a passing emissions test and a fail. You can pair this with Nissan Patrol – Patrol GR Technical Specifications if you are also working on a Patrol.

Diagnóstico de Fallas – Troubleshooting That Works

The DIAGNOSTICO DE FALLAS section (SC y CE-31) uses a sequence-of-operations chart — not a generic flowchart. It tells you how to read the electrical diagrams in the IG section and where to find the power distribution circuit in the SE section. That level of cross-referencing is why this manual matters on the bench. If you have a D-21 that cranks but won’t start, start there. Also check Nissan Altima SRS Airbag Control System Service Manual if you are also dealing with SRS systems, and Nissan Truck 720 PL720 2WD L4 2.0 Z20 Technical Info for similar-era Nissan trucks.

For a broader understanding of automotive systems, read the Automotive Industry Overview. If you need transmission specifics, the Manual Transmission article covers clutch and gearbox basics.

Source Validity: Genuine Nissan Technical Manual

This is an original factory publication — not a reprint, not a scanned copy with missing pages. The document title is Nissan_D-21_Technical_Manual_es-22813017835.pdf and it contains the complete SECCION SC y CE (Sistema de Control de Combustible y de Control de Emisiones). I trust OEM docs because they have the exact torque sequences and diagnostic charts that aftermarket books either paraphrase or leave out. If you want to pass an inspection on a 1990s Hardbody, you need factory data.

Does this manual cover the D-21 engine control system?

Yes, it covers the entire fuel and emission control system, including the ECU, injectors, idle speed, ignition timing, mixture adjustment, evaporative emissions, and crankcase ventilation. It is section SC y CE from the factory manual.

What torque specs are listed?

Torque values are given in the DATOS Y ESPECIFICACIONES DE SERVICIO (D.E.S.) section. Specific numbers are not listed in the index, but the manual includes them for injector hold-down bolts, fuel line fittings, and sensor mounts. You must refer to page SC y CE-158.

Is this a genuine OEM manual?

Yes. This is a direct scan of the original Nissan publication. It has the same part numbers, tool numbers, and Spanish-language text as the dealer version.

Can I use this for a 1990 D-21?

Yes. The D-21 chassis was produced from 1986 to 1997. This manual applies to all D-21 models equipped with the fuel-injected engine and the emission control system described in the table of contents.

Final word: if you are tired of fighting aftermarket wiring diagrams that don’t match your truck’s year, get the real document. Access the Factory Manual and put it on your tablet or print the pages you need. Your D-21 will run cleaner, pass inspection, and you won’t waste afternoons chasing phantom codes.