1990 Toyota 1PZ, 1HZ, 1HD-T Engine Repair Manual (P/N RM172E)

• Toyota factory repair publication, Pub. No. RM172E — 348 PDF pages. The title page identifies the first printing as February 8, 1990 and the 34th printing as August 28, 2001.
• Engine and model coverage: 1PZ, 1HZ, and 1HD-T engines used in PZJ70, PZJ73, PZJ75, HZJ70, HZJ73, HZJ75, HZJ80, HDJ80, HZB30, and HDB30 Land Cruiser and Coaster series.
• Internal engine repair: tune-up, compression testing, timing-belt and timing-gear service, cylinder-head removal/overhaul/installation, cylinder-block teardown and assembly, crankshaft/piston/connecting-rod inspection, and oil-seal replacement.
• Fuel injection and turbo systems: separate nozzle procedures for 1PZ/1HZ and 1HD-T, VE injection-pump teardown and test-stand adjustment, fuel-heater diagnosis, 1HD-T turbocharger service, and HZJ80 turbo warning-light diagnosis.
• Cooling, lubrication, starting, and charging: water pump, thermostat, radiator, oil-pressure and oil-pump service, oil cooler/nozzles, preheating controls, and starter/alternator circuit testing and overhaul.
• Factory reference material: component exploded views, system circuits, diagnostic charts, engine-specific service specifications, standard bolt torque tables, and SST/SSM listings with Toyota part numbers.

Exact Engine and Configuration Coverage

This manual addresses the 1PZ 3.5-liter inline-five and the 1HZ and 1HD-T 4.2-liter inline-six OHC engines, including the swirl-chamber 1PZ/1HZ and direct-injection turbocharged 1HD-T. Toyota separates M/T and A/T data where engine-side tune-up, cooling, or injection-pump settings differ. Pump procedures distinguish HAC-equipped 1PZ/1HZ units from 1HD-T versions with BACS or PCS. Separate operations cover ACSD, dash-pot, thermo-wax, and A/C idle-up hardware, including the HDB30 M/T-only PCS section.

Engine-mechanical diagnosis covers no-crank/no-start, slow cranking, rough warm idle, stalling, power loss, excessive smoke or fuel use, warm-engine noise, and shutdown faults. Repair coverage then moves through valve-clearance shim selection, injection timing, idle and maximum-speed checks, and compression testing. The timing, head, and block chapters cover belt and gear work, combustion-chamber and valve-guide service, camshaft inspection, head-gasket selection by piston protrusion, piston/rod/bearing measurements, cylinder-bore inspection, crankshaft and bearing selection, and final assembly.

Fuel Injection and Turbocharger Repair Depth

The fuel section goes well beyond filter replacement. It contains fuel-heater circuit checks; removal, leakage and spray-pattern testing, cleaning, disassembly, reassembly, and adjustment of 1PZ/1HZ nozzles; and separate two-spring 1HD-T nozzle procedures for pre-lift and staged opening-pressure setup.

The VE injection-pump chapter spans removal through installation. It documents stand mounting and internal teardown of the delivery valves, plunger, rollers, fuel-cut solenoid, pickup sensor, governor, and timer parts. Reassembly is followed by air-tight testing and adjustment of plunger pre-stroke, internal pressure, timer action, overflow and injection volume, idle/maximum speed, cold-start and fast-idle settings, load-sensing timing, and boost-compensator operation. Toyota states that injection-pump repair requires specialized skill and a suitable test bench—an important scope point for anyone planning pump work.

For the 1HD-T, the turbocharger section includes operating and waste-gate diagrams, troubleshooting for low boost or power loss, abnormal noise, and oil consumption, HZJ80 warning-lamp diagnosis, removal, shaft and wheel inspection, actuator testing, pre-lubrication, and installation.

Cooling, Lubrication, and Engine Electrical

Cooling coverage includes coolant service, water-pump removal and inspection, fluid-coupling checks, thermostat testing, radiator cleaning, and cap/system pressure testing. The lubrication section provides oil-pressure diagnosis, oil-pump teardown and rotor-clearance inspection, oil-cooler, relief-valve and check-valve service, and piston oil-nozzle checks.

Starting-system content is configuration-specific. It distinguishes Super Glow and Fixed Delay preheating systems, Europe/Australia and other-market layouts, PZJ/HZJ/HDJ versus HZB/HDB relay arrangements, and 12-volt/24-volt starter applications. Circuit diagrams and timer-characteristic charts support checks of glow relays, plugs, resistor, water-temperature sensor, starter relays, voltage-converter timer/relay, and the 24-volt hold-warning relay. The charging section covers circuit diagnosis, on-vehicle output and warning-light tests, and alternator disassembly, rotor/stator/brush/rectifier/bearing inspection, reassembly, and final checks.

Diagrams, Specifications, Tools, and Scope

Useful visual references include timing-belt and timing-gear layouts, cylinder-head and cylinder-block exploded assemblies, turbocharger section and waste-gate views, VE pump component breakdowns, oil-flow charts, and preheating/starting/charging circuits. Separate specification pages consolidate clearances, wear limits, pressure and injection-volume data, fluid capacities, adjustment settings, electrical test values, and component-specific torque data, followed by standard bolt torque tables.

The SST/SSM appendix identifies the injection-pump tool set 09260-54012, 1HD-T two-spring nozzle tool set 09268-17010, 1PZ/1HZ nozzle wrench set 09268-64010, valve-clearance adjusting tool 09248-64011, compression gauge set 09992-00024, and turbocharger pressure gauge 09992-00241, along with specified sealants and application points.

Toyota warns not to rotate the crankshaft at a specified timing-belt installation stage because the valve heads can strike the piston tops. The VE pump pages prohibit touching precision delivery-valve/plunger sliding surfaces or changing roller positions; mishandling can damage matched parts and invalidate calibration. The turbo section requires clean, plugged ports and pre-oiling during replacement because dirt can damage the high-speed wheels and a dry first start can damage the bearings.

This is an engine repair manual, not a full Land Cruiser or Coaster vehicle manual. M/T and A/T references cover engine-related differences; transmission overhaul, transfer case, axle, brake, body, and full-vehicle wiring procedures are outside this publication. Before internal engine, turbocharger, starter, or alternator repair, follow Toyota’s precautions, isolate electrical power when required, support heavy components correctly, and use the specified tools.