Signed in as:

filler@godaddy.com

Account

Manual Application 1UZ-FE Wiring

Manual Application 1UZ-FE Wiring – Service Discontinuation Notice

🚨 IMPORTANT NOTICE: We have officially discontinued our standalone wiring service for the 1UZ-FE non-VVT engine.

This decision was made due to ongoing issues with the original ECUs for these engines. Many of these ECUs now require rebuilding, which can lead to unforeseen expenses for customers. Unfortunately, we do not offer ECU rebuilding services, and even professional rebuilders cannot guarantee that a rebuilt ECU will function correctly.

Recommended Alternatives

If you’re looking for a reliable and supported Toyota UZ swap, we recommend:
✅ 1UZ-FE VVT-i (Newer and more tunable than the non-VVT version)
✅ 2UZ-FE (Ideal for swaps needing more torque and displacement)
✅ 3UZ-FE (Great for high-performance applications with better ECU support)

We fully support these engines with our programming and wiring services, allowing for a seamless swap experience with a standalone setup, ECU tuning, and immobilizer removal.

What Our 1UZ-FE Wiring Service Previously Included

Our standalone wiring conversion allowed the 1UZ-FE non-VVT engine to function as an independent system in any vehicle. With our modifications, customers could start the engine on the garage floor with just two wires and a fuel pump.

Key Features of the Service

🔧 Fuse Box Integration
We integrated a fuse box into the engine harness, replicating the original vehicle’s wiring layout. This fuse box contained all necessary relays and fuses, ensuring a clean and reliable standalone setup.

🔧 Diagnostics Support

Non-VVT (Pre-1995): Included a built-in LED diagnostics system in the fuse box that flashed out codes (OBD1).
Non-VVT (1995+): Provided OBD2 access through a diagnostic connector, allowing customers to read codes via a scan tool or mobile app.
1997 Non-VVT Exception: This model included an immobilizer, requiring additional programming to function in a swap.

🔧 Harness Cleanup & Customization
We thoroughly inspected, cleaned, and modified the harness by:
✅ Removing unnecessary circuits like EGR (unless requested to keep it)
✅ Replacing damaged or worn-out connectors upon customer request
✅ Wrapping the entire harness in high-quality cloth tape for a professional finish and durability

🔧 Testing & Documentation
Every harness was tested on one of our in-house test engines before shipping to ensure it functioned properly. Customers received:
✅ A test-run video showing the harness in action
✅ Detailed pictures of the completed harness
✅ A shared folder containing:

Welcome Pack
Client Plug Pinouts
Return Shipping Label
Any additional documentation

Client Plug – Easy Vehicle Integration

To simplify installation, we provided a client plug pigtail, making it easy to connect the harness to the vehicle. This plug included:

Engine Power Wires: Ignition, fuel pump power, and start signal
Dashboard Outputs: Charge light, tachometer signal, oil light, and temperature gauge

Parts Required for the Service

Customers were required to send in:
✔️ Their engine harness and ECU
✔️ (Optional) Starter harness and front harness (for non-VVT engines, if they wanted them serviced)

Previous Turnaround Time & Pricing

Before discontinuation, the standard turnaround time was 2-3 weeks, depending on workload.

💰 Previous Pricing:

LS400 Wiring Modification: $590
SC400 Wiring Modification: $690 (SC400 harnesses required extensive reconstruction for swaps)
Connector Replacements: Priced separately, averaging $6 each installed

If the customer had the ECU-to-body connectors, they were encouraged to send them along with the harness.

Final Notes on Discontinuation

While we are no longer offering this service, we continue to support wiring and programming for the 1UZ VVT-i, 2UZ-FE, and 3UZ-FE engines. These engines offer better reliability, tuning flexibility, and ECU support, making them a superior choice for modern swaps.

If you’re looking for a supported UZ-series swap, feel free to reach out, and we’ll be happy to guide you through the process!

Thank you to everyone who has trusted us with their 1UZ-FE swaps over the years!

An example of what you will receive in video:

1UZ-FE Manual Setup Wiring (Scott's S13 Engine Swap) (youtube.com)

1UZ-FE OEM ECU Reliability

We would like to inform you that the service for modifying 1UZ non-VVT engine harnesses is discontinued. This decision has been made due to the fact that the ECUs for these engines often require a rebuild, which can lead to unforeseen expenses for the customer. We do not offer computer rebuilding services, and unfortunately, ECU rebuilders cannot guarantee that your rebuilt ECU will function as expected.

As an alternative, we recommend opting for aftermarket engine management for non-VVT 1UZ engines. This approach eliminates the risk of unexpected costs and provides you with a programmable ECU. It’s important to note that the OEM non-VVT 1UZ ECUs have read-only memory and cannot be modified. This makes aftermarket solutions a more flexible and reliable choice for managing your engine’s performance.

Back to Wiring Services

Additional Information

The Toyota 1UZ-FE 4.0L Engine: Specifications and Reliability

The 1UZ-FE, the first in the UZ engine series, was a 4.0-liter V8 gasoline engine featured in Toyota and Lexus luxury and sports cars from 1989 to 2002, before being replaced by the 3UZ-FE engine. It succeeded Toyota's older V family engines, which were used from the 1960s through the 1990s. The 1UZ-FE engine is characterized by an aluminum cylinder block with thin cast-iron cylinder liners and a 90-degree angle between the cylinder banks, offset by 21 mm. It features six main bearings and a forged steel crankshaft with eight counterweights. To minimize rotational mass, it includes lightweight forged steel connecting rods, aluminum pistons, and induction-hardened connecting rod pins. In late 1994, the 1UZ-FE received updates such as a lighter crankshaft, connecting rods, shorter piston pins, and redesigned pistons. Its quiet and smooth operation is largely due to liquid-filled compound engine mounts. In 1997, it was further refined with a more rigid cylinder block to enhance quietness.

The 1UZ engine is engineered more like a racing powerhouse than your typical road car engine. It's equipped with an eight counterweight crankshaft, and its components are designed to be lightweight. The bore and stroke dimensions are almost perfectly square, which is quite unique. But the standout feature has to be the DOHC 32-valve aluminum cylinder heads. This is a stark contrast to the older V8 engines, which usually had a single camshaft in the cylinder block and OHV heads with just two valves per cylinder. The 1UZ-FE, on the other hand, features two camshafts per head—one for intake and one for exhaust, with four valves for each cylinder. The intake camshafts are belt-driven, while the exhaust camshafts are gear-driven by the intake ones. Instead of using hydraulic lifters, this engine uses solid aluminum alloy valve lifters and steel outer shim type valve adjusters. Initially, the valve stem diameter was 6.0 mm for both intake and exhaust valves, with the intake valves being 33.5 mm in diameter and the exhaust valves 28.0 mm. But in a late 1997 update, the valve diameters were increased to 34.5 mm for intake and 29.0 mm for exhaust, and the stem diameter was reduced to 5.5 mm.

The initial design of the 1UZ-FE engine showcased a simple ignition system, comprising two distributors along with two ignition coils. This engine initially employed multi-port fuel injection (MFI) technology until 1994, which was then upgraded to sequential multiport fuel injection (SFI). The Non-VVT-i variant came with a mechanical throttle body and was fitted with an aluminum intake manifold. Additionally, it featured an Exhaust Gas Recirculation (EGR) system, which was responsible for redirecting a portion of the exhaust gases back into the combustion chambers. These gases were cooled by the engine's coolant system located at the rear before re-entry. However, the EGR system was phased out in 1997. As for the exhaust configuration, it boasted stainless steel headers and monolithic-type three-way catalytic converters.

Engine Specifications:

- Manufacturer: Tahara plant

- Production Years: 1989-2002

- Cylinder Block Material: Aluminum

- Cylinder Head Material: Aluminum

- Fuel Type: Gasoline

- Fuel System: Fuel injection

- Configuration: V

- Number of Cylinders: 8

- Valves Per Cylinder: 4

- Valvetrain Layout: DOHC

- Bore: 87.5 mm (3.44 in)

- Stroke: 82.5 mm (3.25 in)

- Displacement: 3,968 cc (242.1 cu in)

- Engine Type: Four-stroke, naturally aspirated

- Compression Ratios:

- 10.0:1

- 10.4:1 (since late 1994)

- 10.5:1 (since 1997 for VVT-i engines)

- Power Output:

- 251-261 hp (191-195 kW) at 5,400 rpm (non VVT-i)

- 290-300 hp (216-224 kW) at 5,900-6,000 rpm (with VVT-i)

- Torque:

- 260-269 lb-ft (353-365 Nm) at 4,400 rpm (non VVT-i)

- 300-310 lb-ft (407-420 Nm) at 4,000-4,100 rpm (with VVT-i)

- Engine Weight: 364 lbs (165 kg)

- Firing Order: 1-8-4-3-6-5-7-2

- Engine Oil Weight: 5W-30

- Engine Oil Capacity:

- 5.0 liters (0.3 for oil filter) for 1989-1994 models

- 5.1 liters (0.3 for oil filter) for 1994+ models

- Oil Change Interval:

- 6,000 miles (10,000 km) or 12 months for 1989-1994 models

- 9,000 miles (15,000 km) or 12 months for 1994+ models

- Applications: Lexus GS 400, Lexus LS 400, Lexus SC 400, Toyota Aristo, Toyota Celsior, Toyota Crown, Toyota Soarer