Reference-Grade Manual: 1991 Mitsubishi 3000GT / SL / VR-4 Service Manual Documentation-Framework

Operational-Framework: Mitsubishi 3000GT, 3000GT SL & 3000GT VR-4 — 1991 // Service-Level: Engine, Chassis & Body / Electronic Control Logic // Product-Line: V60° DOHC Architecture (2,972 cc displacement / Multi-Point Injection).

Integrated service sections encompass engine mechanical disassembly procedures, covering fuel system architecture, detailing cooling system maintenance, examining emission control networks, and referencing transmission assemblies.

Verification procedures are included for compression pressure testing across all six cylinders of the 3,972 cc V-configuration powerplant. The manual provides technical reference data for the multi-point injection system, incorporating air flow sensor calibration values, throttle position sensor adjustment protocols, and idle speed control servo specifications. Repair information is provided for camshaft oil seal replacement, timing belt installation sequences, and crankshaft bearing clearance measurements. The document includes coverage of the electronic control suspension system with stepper motor diagnostics and position sensor verification. Brake system specifications are included for disc brake pad thickness limits, hydraulic pressure testing procedures, and anti-lock brake signal integration. Safety procedures are documented for supplemental restraint system component handling, air bag module removal sequences, and clock spring connector service protocols.

The architecture of the 6G72 DOHC engine is presented through sectional diagrams illustrating the dual overhead camshaft configuration with 24-valve arrangement. Consistent technical specifications define the compression ratio at 10.0:1 for non-turbocharged variants and 8.0:1 for turbocharged VR-4 models, with firing order sequence 1-2-3-4-5-6 across both cylinder banks. Service procedures address valve timing specifications, camshaft bearing oil clearance measurements, and piston-to-cylinder bore tolerances. The fuel delivery system documents the Karman vortex air flow sensor operation, electromagnetic injector pulse width modulation, and fuel pressure regulator settings of 335 kPa for non-turbo and 300 kPa for turbocharged applications. Electrical system diagnostics utilize multi-use tester protocols for reading self-diagnosis codes, monitoring sensor voltage outputs, and performing actuator drive tests across engine control unit terminals.

This reference manual documents torque specifications for the engine assembly with cylinder head bolt tightening sequences performed in progressive stages to achieve 120-130 Nm cold-engine values. The manual provides crankshaft main bearing installation procedures, piston ring end gap measurements, and connecting rod bearing oil clearance standards. Transmission service data includes gear ratio specifications for the 5-speed manual F5M33 transaxle with final reduction ratio of 4.153, and the 4-speed automatic F4A33 unit with torque converter stall speed parameters. Chassis documentation addresses front suspension geometry with MacPherson strut removal sequences, and rear multi-link suspension component identification. The document includes coverage of the variable induction control servo utilizing DC motor actuation, waste gate control solenoid valve operation for boost pressure regulation, and EGR temperature sensor circuit diagnostics for California-specification emissions compliance.