The fuel injected 4A-FE is the successor of the carbureted 4A-F. It was manufactured between 1987–2001. Toyota designed this engine with fuel economy in mind. The 4A-FE is basically the same as the 4A-F (introduced in the 6th generation of Corollas), the most apparent difference being the electronic fuel injection system as noted by the E. The engine was succeeded by the 3ZZ-FE, a 1.6-liter engine with VVT-i technology. There are three generations of this engine and can be identified by the external shape of the engine. The first generation (1987–1996) featured a plate on the head which read "16 valve EFI" and fuel injectors in the head.

The second generation had a higher profile cam design in the head, a cam cover with ribs throughout its length, and fuel injectors in the intake manifold runners. Mechanically, the late-model engines received MAP load sensing and redesigned pistons, intake ports, and intake manifold. The second generation engine was produced from 1992–1998 (1993–1996 in the US).

The third generation (1996–2001) was released exclusively for the Asian market (Japan, Philippines, Pakistan, Thailand, Indonesia, and Malaysia) only. Although it is very similar to the second generation externally, it only has a slight difference in the top section of the intake manifold and throttle body. This last generation also has a higher additional output of 4 kW (5 hp; 5 PS) compared to the second generationThe 4A-FE is different from the 4A-GE in terms of performance and power. Although both have the same displacement and are DOHC, they were optimized for different uses. The first obvious difference are the valves, the engine's intake and exhaust valves were placed 22.3° apart (compared to 50° in the G-Engines). The second is that it employed a "slave cam system", the camshafts being geared together and driven off one camshaft's sprocket (both camshafts' sprockets on the G-Engine are rotated by the timing belt). Some of the less directly visible differences were poorly shaped ports in the earlier versions, a slow burning combustion chamber with heavily shrouded valves, less aggressive camshaft profiles, ports of a small cross sectional area, a very restrictive intake manifold with long runners joined to a small displacement plenum and other changes. Even though the valve angle is closer to what is considered in some racing circles to be ideal for power (approximately 25 degrees), its other design differences and the intake which is tuned for a primary harmonic resonance at low RPM means that it has about 10% less power compared to the 4A-GE engine. This engine design improves fuel efficiency and torque, but compromises power. Power rating varied from 75–78 kW (100–105 hp; 101–106 PS) in the US market. Late-model engines are rumored to make slightly greater power but still received a 78 kW (105 hp; 106 PS) rating.

### Gearbox Reconditioning on a 4A-FE Toyota Engine

#### **Understanding the Gearbox**

**1. Theory Behind the Gearbox:**
The gearbox (or transmission) in a vehicle is responsible for transferring power from the engine to the wheels. It allows the engine to operate efficiently at various speeds. The gearbox changes the gear ratio, enabling the vehicle to accelerate from a standstill and maintain speed efficiently.

**2. Components of the Gearbox:**
- **Gears:** Different sizes and shapes that change the speed and torque.
- **Shafts:** Transfer power between components.
- **Synchronizers:** Help gears engage smoothly.
- **Bearings:** Support rotating parts and reduce friction.
- **Seals:** Prevent fluid leaks.
- **Oil:** Lubricates components, ensuring smooth operation.

#### **Why Recondition?**
Over time, wear and tear can lead to:
- **Worn Gears:** Can cause slipping or difficulty shifting.
- **Damaged Bearings:** Can lead to noise and poor performance.
- **Fluid Leaks:** Reduces lubrication effectiveness.
- **Contaminated Oil:** Can cause overheating and wear.

Reconditioning helps restore the gearbox's efficiency, prolonging its life and ensuring smooth operation.

#### **Reconditioning Process**

**Tools and Materials Needed:**
- Socket set
- Screwdrivers
- Pliers
- Torque wrench
- Gear oil
- Cleaning solvent
- Replacement parts (gaskets, seals, bearings, gears as needed)
- Workbench and clean cloths

**Step-by-Step Process:**

1. **Preparation:**
- Disconnect the battery to avoid electrical issues.
- Drain the gearbox oil by removing the drain plug. Allow it to fully drain into a container.

2. **Remove the Gearbox:**
- Support the vehicle on jack stands.
- Disconnect the driveshaft from the gearbox.
- Remove any electrical connections, cables, and linkage.
- Unbolt the gearbox from the engine block and carefully lower it.

3. **Disassemble the Gearbox:**
- Place the gearbox on a clean workbench.
- Remove the outer casing by unbolting it. Keep track of all screws and components.
- Carefully take out the gears, shafts, and bearings. Use a magnetic tray to organize small parts.

4. **Inspect Components:**
- Check gears for wear (scoring or pitting).
- Examine bearings for play or damage.
- Look for signs of oil contamination or sludge buildup.
- Inspect seals for wear—replace them if cracked or brittle.

5. **Clean All Parts:**
- Use a cleaning solvent to thoroughly clean all components.
- Remove old gasket material from the casing.
- Ensure all parts are free from debris and oil residue.

6. **Replace Worn Components:**
- Install new bearings, seals, and gaskets as needed.
- Replace any damaged gears or shafts. Ensure they match OEM specifications.

7. **Reassemble the Gearbox:**
- Carefully position all components back into the casing.
- Apply gasket sealant where needed.
- Reattach the outer casing and torque bolts to manufacturer specifications.

8. **Reinstall the Gearbox:**
- Lift the gearbox back into position under the vehicle.
- Reconnect it to the engine block, driveshaft, and any electrical connections.
- Ensure everything is tightened securely.

9. **Refill Gearbox Oil:**
- Fill the gearbox with the correct type and amount of oil (check the manual for specifications).
- Check for leaks around seals and connections.

10. **Test Drive:**
- Reconnect the battery.
- Start the engine and allow it to warm up.
- Test drive the vehicle to ensure smooth shifting and listen for any unusual noises.

#### **What Can Go Wrong?**
- **Poor Assembly:** Misalignment can lead to premature wear.
- **Neglecting to Replace Worn Parts:** Can result in recurring issues.
- **Improper Fluid Levels:** Can cause overheating and failure.
- **Ignoring Noise or Shifting Problems:** Can lead to complete gearbox failure.

### **Conclusion**
Reconditioning a gearbox is a meticulous process that requires attention to detail. By understanding the components and their functions, you can tackle this repair confidently. Always refer to specific service manuals for your vehicle to ensure accuracy and safety.
rteeqp73

### Transmission Fluid Pressure Test on a 4A-FE Toyota

#### Theory Behind the Test:

The transmission in your vehicle uses fluid to operate. This fluid is crucial for lubricating moving parts, providing hydraulic pressure to engage gears, and aiding in cooling. If the pressure is too low or too high, it can lead to shifting problems, overheating, or damage to the transmission.

#### Components Involved:

1. **Transmission Fluid**: The lifeblood of your transmission, it lubricates, cools, and provides the hydraulic pressure needed for gear engagement.

2. **Transmission Pressure Port**: A specific point on the transmission where you can measure fluid pressure.

3. **Pressure Gauge**: A tool that measures the fluid pressure in the transmission. It usually has a dial or digital readout.

4. **Pressure Test Kit**: This often includes a gauge and necessary fittings to connect to the pressure port.

5. **Transmission Control Module (TCM)**: An electronic component that regulates the operation of the transmission based on various inputs.

6. **Transmission Filter**: Helps keep the fluid clean and free of debris, ensuring proper flow and pressure.

#### Steps for the Pressure Test:

1. **Preparation**:
- **Tools Needed**: Pressure test gauge, wrenches, safety glasses, gloves, and a drain pan.
- **Safety First**: Ensure the vehicle is on a flat surface and securely supported. Wear gloves and safety glasses.

2. **Locate the Pressure Port**:
- Find the transmission on the 4A-FE. The pressure port is usually located on the transmission body. Consult the service manual for exact location.

3. **Connect the Pressure Gauge**:
- Remove the pressure port's plug using the appropriate wrench.
- Attach the pressure gauge to the port. Ensure a snug fit to avoid leaks.

4. **Warm Up the Engine**:
- Start the engine and let it idle until it reaches normal operating temperature. This ensures the fluid is at the correct viscosity.

5. **Check Fluid Level**:
- With the engine running, check the transmission fluid level using the dipstick. The fluid should be at the correct level for accurate testing.

6. **Conduct the Pressure Test**:
- With the gauge connected, shift through the gears (P, R, N, D) while observing the pressure readings.
- In Drive, the pressure should typically be between 50-70 psi (check specific values for your model).
- Note the readings and compare them to the manufacturer’s specifications.

7. **Analyze the Results**:
- **Low Pressure**: Could indicate a fluid leak, clogged filter, or pump failure.
- **High Pressure**: May suggest a blockage in the system or a malfunctioning TCM.

8. **Disconnect and Clean Up**:
- Once testing is complete, turn off the engine, carefully remove the gauge, and reinstall the pressure port plug.
- Dispose of any spilled fluid properly and clean the area.

#### What Can Go Wrong:

1. **Low Pressure**:
- **Causes**: Fluid leaks, worn pump, or clogged filter.
- **Symptoms**: Slipping gears, delayed engagement.

2. **High Pressure**:
- **Causes**: Blocked passages or failing components in the hydraulic system.
- **Symptoms**: Harsh shifting or overheating.

3. **Fluid Contamination**:
- Old or contaminated fluid can affect pressure readings and overall transmission performance.

4. **Faulty TCM**:
- If the TCM is not sending the correct signals, it may cause abnormal pressure levels.

### Conclusion:

Performing a transmission fluid pressure test is essential for diagnosing transmission issues. By understanding the components and following the steps carefully, you can assess the health of your transmission system effectively. Keep in mind that proper fluid maintenance is critical to avoid problems in the future.
rteeqp73