1vd injectors

Toyota 1VD Injectors Guide

1. Pre-DPF Injectors (Solenoid-Type)

Overview

The earlier Toyota 1VD engines, primarily in the pre-DPF models, use solenoid-controlled injectors. These injectors have been around for years and are well-known for their robust design. However, they come with certain limitations when faced with Australia’s tough conditions, particularly in extreme heat, dust, and poor fuel quality environments.

How They Work

Solenoid injectors rely on a magnetic coil to control fuel injection, opening and closing to regulate fuel delivery. While this is a time-tested technology, the larger internal moving parts can present challenges over time, particularly in conditions where contaminants or low-quality fuel are present.

Strengths

Robust Electronics: Solenoid injectors are highly reliable from an electronic perspective. The coil system that controls the injectors is simple and less prone to electrical failures, which means solenoid injectors have a longer lifespan when it comes to electrical components.

Weaknesses

  • Susceptibility to Seizure: One significant downside of solenoid injectors is their larger internal moving parts, which can make them more prone to seizure-related failures. This is particularly relevant in Australia’s harsh environments where heat, dust, and poor fuel conditions can exacerbate this issue. Over time, these factors make the injectors more likely to malfunction.

Cold Knock Symptoms: Solenoid injectors are also known for causing what is commonly referred to as "Toyota Cold Knock." This happens when the injectors struggle to deliver fuel efficiently during cold starts, leading to a knocking noise that fades as the engine warms up. It’s a well-documented problem in the 1VD engine, and timely injector maintenance and replacement can prevent further damage.

Maintenance Tips

  • Regular Maintenance: Keeping solenoid injectors clean and using high-quality diesel fuel are crucial for extending their life. Regular cleaning and maintenance are essential, especially if your vehicle is exposed to tough conditions like dust or extreme temperatures.
  • Fuel Lubricity and Filtration: Adding lubricity to your fuel can help protect solenoid injectors, especially in Australia where fuel quality can be inconsistent. Installing a 2-micron secondary fuel filter can also help keep contaminants from reaching the injectors, reducing the risk of wear and tear.

Monitoring for Symptoms: Early detection is key to preventing severe injector damage. Regularly check for signs such as rough idling, reduced fuel economy, or unusual knocking sounds. Monitoring injector feedback values as part of your routine maintenance can help identify issues early.

2. Post-DPF Injectors (Piezo-Type)

Overview

With the introduction of the DPF (Diesel Particulate Filter) system, Toyota upgraded the 1VD engine to piezo-electric injectors. These are far more advanced and precise compared to solenoid injectors, but they come with their own set of challenges. Australian conditions can expose these injectors to unique failure modes, especially when fuel quality is inconsistent.

How They Work

Piezo injectors use a piezoelectric crystal to control fuel delivery, allowing for incredibly precise injections with multiple deliveries per combustion cycle. While this provides improved efficiency and emissions control, the technology is more sensitive to fuel quality and operating conditions.

Strengths

  • Mechanically Robust: Piezo injectors are considered more robust and reliable from a mechanical perspective. Their design helps them withstand the common failure modes seen in Australian conditions, making them more efficient in delivering fuel and maintaining engine performance.

Precise Fuel Delivery: These injectors are more accurate than solenoid injectors, which results in smoother engine operation, better fuel efficiency, and reduced noise. The piezo system also helps meet the stricter emissions standards required by DPF-equipped engines.

Weaknesses

New Failure Modes: While piezo injectors have addressed some of the limitations of solenoid injectors, they have introduced new failure modes that differ between the 70 Series and the 200 Series Land Cruisers:

    • P1238 Injector Malfunction (70 Series): Many 70 Series owners have reported receiving P1238 fault codes, which indicate injector malfunction. If not addressed promptly, these issues can lead to performance degradation.
    • Excessive Smoke (200 Series): In the 200 Series, one of the most commonly reported issues is excessive smoke caused by over-fueling. This problem tends to worsen as the vehicle accumulates mileage and is often related to injector performance.

 

Interestingly, both the 70 and 200 Series share identical fuel systems and injectors, but these failures have been prevalent enough that Toyota Australia has struggled to meet the demand for injector replacements under warranty claims. At one point, it became difficult to purchase a complete set of 8 injectors in Australia, and Toyota required VIN numbers just to supply one or two injectors.

Part Supply Challenges: Injector supply in Australia is still relatively tight due to high demand for replacements. However, Diesel Geeks sources parts from Denso distributors around the world, ensuring that we are less susceptible to local supply shortages.

Maintenance Tips

  • Use High-Quality Diesel: The precision of piezo injectors means they are highly sensitive to fuel quality. Using premium diesel and additives that improve fuel lubricity can help prolong the life of the injectors. 2 micron secondary filters will also minimise contaminants flowing through the injection system thus minimising the associated wear. 

Regular Injector Testing: Due to the advanced design of piezo injectors, regular testing is recommended to catch issues early. Look out for early warning signs like reduced power or fuel efficiency. For 70 Series owners, prompt action on P1238 codes can prevent further damage, while 200 Series owners should monitor for excessive smoke.