The Toyota 1N is a 1,453 cc, inline‑three, naturally aspirated diesel engine produced between 1986 and 1999. It features a cast iron block, overhead camshaft (SOHC) design, and indirect injection via a mechanically controlled CAV or Bosch injection pump. This simple, robust architecture prioritised fuel economy and durability for compact vehicles.
Fitted to models such as the Starlet (KP60, KP70) and Tercel (EL30, EL40), the 1N was engineered for economical, reliable urban transportation. Emissions compliance for its era was managed through basic pump calibration and mechanical timing, meeting applicable Japanese and export market standards of the time.
One documented concern is potential wear of the mechanical fuel lift pump diaphragm, which can lead to fuel starvation and hard starting. This issue, noted in Toyota Service Bulletin TB‑89‑05 for certain high‑mileage applications, is often linked to age and exposure to modern bio-diesel blends.
Production years 1986–1999 meet applicable Japanese and export market emissions standards for their respective model years (Toyota Engineering Specification TES‑101).
The Toyota 1N is a 1,453 cc inline‑three SOHC diesel engine engineered for subcompact hatchbacks and sedans (1986-1999). It combines a simple mechanical injection system with a three-cylinder layout to deliver exceptional fuel efficiency and low running costs. Designed to meet the emissions standards of its production era, it prioritised mechanical simplicity and ease of repair.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 1,453 cc | |
| Fuel type | Diesel | |
| Configuration | Inline‑3, SOHC, 6‑valve | |
| Aspiration | Naturally aspirated | |
| Bore × stroke | 79.0 mm × 98.5 mm | |
| Power output | 38–42 kW (51–57 PS) | |
| Torque | 98–105 Nm @ 3,000 rpm | |
| Fuel system | Indirect injection, mechanical CAV/Bosch pump | |
| Emissions standard | Applicable standards for model year (e.g., Japan 1990) | |
| Compression ratio | 22.0:1 | |
| Cooling system | Water‑cooled | |
| Turbocharger | None | |
| Timing system | Belt‑driven | |
| Oil type | SAE 15W‑40 or 20W‑50 (mineral, API CC) | |
| Dry weight | 115 kg |
The three-cylinder design offers inherent fuel efficiency but produces noticeable vibration at idle. The timing belt must be replaced at the specified interval (typically 60,000-80,000 km) to prevent catastrophic failure. The mechanical fuel lift pump is a known wear item; inspect and replace if hard starting occurs per Service Bulletin TB-89-05. Using the specified mineral oil (15W-40/20W-50) is essential for protecting older engine components.
Oil Specs: Requires mineral-based SAE 15W-40 or 20W-50 meeting API CC specifications (Toyota Owner's Manual).
Emissions: Meets applicable standards for model year and market (Toyota Engineering Spec. TES-101). No formal Euro standards apply.
Power Ratings: Measured under JIS D 1001 standards. Output varies by specific model application and pump calibration (Toyota Global Catalogue).
Toyota Repair Manual RM111U (Starlet KP70/Tercel EL40)
Toyota EPC (Electronic Parts Catalogue) Documentation
Toyota Global Engine Catalogue (1995 Edition)
Toyota Service Bulletin TB-89-05
The Toyota 1N was used across Toyota's Starlet and Tercel platforms with transverse mounting. This engine received platform-specific adaptations-different engine mounts for the Tercel sedan and revised accessory brackets for the Starlet hatchback-creating minor service part variations. All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped on the front of the engine block, near the timing cover. The full engine designation (e.g., 1N) is often found on a metal plate attached to the firewall. Visually, the 1N is identified by its compact, three-cylinder cast iron block, SOHC valve cover, and the prominent mechanical injection pump mounted on the side. Differentiate from the 2N by its smaller displacement (1.5L vs 1.8L) and from the 1K by its diesel fuel system and three cylinders.
The 1N's primary reliability risk is mechanical fuel lift pump failure, with elevated incidence in high-mileage or poorly maintained examples. Toyota service data indicates a notable number of pump replacements were performed under bulletin TB-89-05, while owner reports frequently cite timing belt failures stemming from neglected maintenance. Extended oil change intervals can lead to sludge and accelerated wear, making adherence to the service schedule critical.
Analysis derived from Toyota technical bulletins (1986-1999) and owner workshop manuals. Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about TOYOTA 1N.
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