Mitsubishi 4G61, 4G63 & 4G64 Engine Overhaul (1992) | Manual Collection

Use the engine overhaul chapters for bench work and the separate transaxle, diagnostic, and wiring references for the vehicle or assembly identified in each excerpt.

The 1992 chapter covers internal engine overhaul, including naturally aspirated and turbocharged 4G63 DOHC configurations. Its electrical coverage consists of component checks and terminal illustrations. Vehicle-specific engine removal and ECU fault-code diagnosis are outside that chapter’s scope. The collection provides selected references for several vehicles. It does not provide complete factory workshop coverage for the Lancer Evolution I–III.

PDF Search, Diagram Legibility, and Files

Search and diagrams: The service PDFs have OCR text search, with gaps on some diagram pages. The two decal sheets have no searchable text. There are no embedded PDF bookmarks. Small connector and wire labels often need zooming. Parts of the SOHC cross-section and two Galant wiring diagrams display with gaps or bands. Some Eclipse/Spyder radio wiring details remain faint when enlarged.

The ZIP contains 33 printable PDFs totaling 2,192 pages. That total includes the two decal sheets and 289 pages in three duplicate PDFs. The ZIP also includes two 4WD diagrams in GIF format and a separate Active Yaw Control reference in WPS format for the Evolution IV and later.

Engine Rebuilds, Transaxles, and Electrical Checks

The following selected service topics show the range of the collection. The Eclipse/Spyder excerpts also cover rear axle service for front- and all-wheel-drive layouts.

• Timing belts: Separate SOHC and DOHC procedures cover belt inspection, tensioner setup, and balance-shaft timing, with instructions for configurations with and without silent shafts.

• Cylinder heads: Valve-seat reconditioning and replacement, valve-guide replacement, camshaft and rocker-arm inspection, and lash-adjuster air bleeding and leak-down testing.

• Short block: Piston-pin removal and installation, piston-ring inspection, cylinder boring, and plastic-gauge checks of connecting-rod and crankshaft main-bearing oil clearances.

• Lubrication: Front-case procedures cover oil-pump gear inspection, silent-shaft bearing replacement, oil-pan resealing, and oil-cooler bypass-valve testing.

• Turbocharger: Disassembly and reassembly cover the turbine housing, compressor cover, wheel assembly, and wastegate actuator operation check.

• Transaxles: Manual transaxle procedures cover synchronizers and AWD center differentials. Separate Eclipse/Spyder material covers F4AC1 automatic transaxle diagnosis and overhaul.

• Electrical diagnosis: Laser/Talon excerpts cover charging, starting, and fuel-system troubleshooting. Galant and Eclipse/Spyder references include wiring diagrams and component or connector locations.

This collection is suited to technicians and experienced rebuilders. During a 4G6 overhaul, the inspection procedures and service limits help determine whether a cylinder head needs resurfacing or a bearing clearance calls for further inspection.

Fuel, Cooling, and Ignition Applications

The 1992 chapter distinguishes GALANT/EXPO and TRUCK SOHC fuel-system layouts. Throttle-body procedures separate the EXPO unit from the GALANT/TRUCK SOHC design and the DOHC stepper-motor arrangement. Component checks cover injectors, EGR operation, throttle-position sensors, and the separate idle-speed-control and idle-air-control motor arrangements.

Sensor installation notes identify ECLIPSE and MIRAGE applications. The turbo injector identification table separates GALANT/ECLIPSE manual-transmission applications from the ECLIPSE automatic-transmission application.

The intake and exhaust sections cover water-pump removal and installation, thermostat housings, coolant-temperature sensors, gauge senders, and turbocharger oil and coolant pipes. The generator and ignition sections cover accessory-drive hardware, SOHC distributor installation, and DOHC crankshaft-position-sensor installation.

Machining, Assembly Drawings, and Special Tools

The inspection tables distinguish standard dimensions from service limits for valve-stem-to-guide clearance, cylinder bores, and piston fit. They also give oversize valve-seat and guide-bore dimensions, the combined cylinder-head and block resurfacing allowance, and assembly torque values, including cylinder-head fasteners. Sealant references and electrical test values accompany the mechanical specifications.

Reassembly notes identify camshafts, rocker arms, bearing caps, and head gaskets by their factory markings. Mounting-bracket drawings separate RWD/4WD from FWD/AWD layouts. The crankshaft exploded view distinguishes flywheel and drive-plate arrangements, and the DOHC throttle-body view shows component order and fastener locations. SOHC and DOHC cross-sections and the DOHC turbo lubrication diagram show the internal layout and oil-cooler connections.

Special-tool references identify MD998440 for lash-adjuster leak-down testing and MD998727 for oil-pan removal. The piston-pin procedure uses MIT216941, cross-referenced to MD998780 in the tool table.

The DOHC camshaft procedure warns that holding the sprocket directly with a tool can damage it. The turbocharger procedure warns that excess test pressure can damage the wastegate actuator diaphragm. Always verify that your lifting equipment and engine stands meet the necessary load ratings before starting a major block teardown or assembly procedure.

Separate Drivetrain and Diagnostic References

The manual transaxle section pairs its vehicle and engine application tables with gearset, synchronizer, and differential procedures. For the non-turbo 420A Eclipse/Spyder, the F4AC1-3-QZAF material includes hydraulic pressure checks and internal transaxle overhaul.

The Galant Active ECS excerpt includes suspension troubleshooting. The Eclipse/Spyder 2.0L turbo and 2.4L fuel-injection excerpt gives ECM terminal layouts, test conditions, and expected readings for connector checks.

Sample Head Flatness and Bearing Clearances

For the SOHC 4G63 and 4G64 cylinder heads, the 1992 chapter lists 0.05 mm as the standard gasket-surface flatness value and 0.2 mm as the service limit.

The same chapter specifies a standard crankshaft main-bearing oil clearance of 0.02–0.05 mm and a 0.1 mm limit for the plastic-gauge check.