Restoring a Nissan Skyline R32, R33, or R34 requires a methodical approach to address decades of thermal fatigue, aging rubber, and specialized drivetrain quirks. Whether you're dealing with an RB26DETT oil pressure drop or a worn ATTESA E-TS hydraulic pump, sorting these Japanese legends demands exact mechanical tolerances. This guide breaks down the core systems, common failure points, and concrete restoration steps to get your Skyline running at factory-fresh performance.
Before turning a single bolt, you need to verify your chassis code and engine specification. Mixing up RB25DET and RB26DETT component clearances or assuming all three generations share identical wiring looms is a fast track to expensive mistakes. Let's dive into the actual wrenching.
Identifying Chassis and Powertrain Specifications
The Skyline lineage spans three major performance generations, each with distinct mechanical quirks.
- BNR32 (1989-1994): Features the iconic RB26DETT twin-turbo inline-six and ATTESA E-TS all-wheel drive. Watch out for thin oil pump drives on early non-N1 blocks.
- BCNR33 (1995-1998): Longer wheelbase, improved oil pump collar, and a stiffer chassis. The active rear steering (HICAS) actuator often develops fluid leaks around the rear subframe.
- BNR34 (1999-2002): The final evolution with a Getrag 6-speed manual transmission, Getrag-sourced drivetrain components, and a robust Getrag/Getrag-supported Getrag layout. It features a multi-function display (MFD) that frequently suffers from backlight inverter failure.
RB Series Engine Overhaul and Diagnostics
The RB engine family is bulletproof when maintained, but high boost and missed oil changes lead to spun bearings and cracked lands.
Compression and Leak-Down Testing
Don't guess engine health. Perform a warm compression test and leak-down test before pulling the motor.
- Warm the engine to operating temperature, then pull all ignition coils and spark plugs.
- Thread your compression gauge into cylinder one, hold the throttle wide open, and crank the engine through four compression strokes.
- Healthy RB engines should show 150 to 170 psi across all cylinders with less than 10% variance.
- If compression is low, pump 15cc of engine oil into the cylinder and retest. If numbers jump, your piston rings are worn; if they stay low, you're looking at leaking valves or a blown head gasket.
Oil Pump Collar Inspection
Early R32 RB26 engines are notorious for oil pump drive failure because the crankshaft snout flat spots are thin. If you're building or servicing an early engine, upgrade to an N1 oil pump and ensure a machined crank collar is installed to prevent catastrophic oil starvation at high RPM. For official maintenance standards, reference the Nissan Global Heritage archives for historical service bulletins.
ATTESA E-TS and Drivetrain Maintenance
The torque-split all-wheel-drive system is what makes the GT-R legendary, but it relies heavily on hydraulic pressure and clean fluid.
- Fluid Flushing: The ATTESA reservoir sits in the trunk alongside the pump. Drain and flush this system using recommended automatic transmission fluid every 30,000 miles. Trapped air or degraded fluid causes jerky torque transfer.
- G-Sensor Calibration: If your 4WD warning light illuminates intermittently during hard cornering, the mechanical or early electronic G-sensors under the center console may be failing or uncalibrated.
Suspension, Bushings, and HICAS Overhaul
Factory rubber bushings on R32 and R33 models are well past their service life. A sloppy suspension ruins the nimble turn-in these cars are famous for.
- Front Upper Control Arms: Factory arms wear out quickly, leading to uneven inner tire wear. Upgrade to adjustable spherical-bearing arms to restore proper camber geometry.
- HICAS Deletion vs. Maintenance: The Super HICAS rear-steer system uses hydraulic actuators. When they leak, steering response becomes unpredictable. Many owners install a HICAS lock-out bar, while purists rebuild the solenoids and bleed the rear steering circuit thoroughly.
For comprehensive regulatory compliance and import standards if you're bringing one across borders, check the National Highway Traffic Safety Administration guidelines on imported vehicle conformity.
Electrical Gremlins and Wiring Harness Repair
Wiring insulation on 90s Japanese sports cars becomes brittle due to engine bay heat cycles.
- Ignition Harnesses: Factory coilpack wiring harnesses bake over time, causing misfires that mimic failing igniter chips. Re-pin the connectors or install a split-fire coil pack upgrade harness.
- Alternator Grounding: Voltage drop is common due to corroded factory ground straps. Run an auxiliary ground wire from the alternator casing directly to the chassis negative terminal to stabilize charging voltage.
Frequently Asked Questions
How often should I change the timing belt on an RB26?
Change the timing belt every 60,000 miles or every 5 years, whichever comes first. Because interference engine designs mean a snapped belt results in bent valves, inspect the tensioner pulleys and water pump during the same service interval.
What causes rough idling on a cold start?
Vacuum leaks around the intake plenum gaskets or a faulty Automatic Air Control (AAC) valve are the primary culprits. Carbon buildup inside the throttle bodies and idle air bypass passages also restricts airflow when the engine is cold.
Can I run modern ethanol-blended pump gas in a stock Skyline?
Avoid high-ethanol fuels (like E85) unless your fuel system has been completely upgraded with ethanol-compatible lines, high-flow fuel pumps, and a proper ECU tune. Factory rubber lines and fuel pressure regulators will degrade rapidly under high ethanol content.
How do I troubleshoot ATTESA 4WD light activation?
Check the ABS fuses, brake pedal switch adjustment, and ATTESA fluid level first. A low fluid level or failing pressure accumulator switch frequently triggers the warning light on the instrument cluster.
