Experiencing a no-start condition in your 1999 Toyota Land Cruiser can be frustrating, especially when it seems to crank perfectly but fails to ignite. Many owners of this robust and reliable SUV may encounter this issue at some point. This guide delves into diagnosing a situation where your 1999 Toyota Land Cruiser cranks but refuses to start, drawing from a real-world scenario to help you troubleshoot effectively.
One owner of a 1999 Toyota Land Cruiser recently reported an abrupt no-start issue. The problem began after a simple maneuver: moving the vehicle from the front to the back of the house. Initially, the Land Cruiser started without a hitch, ran briefly, and then suddenly died while backing into a driveway. There was no sputtering or hesitation, just a sudden silence. Subsequent attempts to restart resulted in backfiring, leading the owner to halt further tries for the day.
The following day, the 1999 Toyota Land Cruiser started again, only to die after about 10 minutes. This pattern of intermittent starting and stalling continued, with the run time decreasing each time. Eventually, a check engine light illuminated, indicating a camshaft position sensor fault. Despite replacing the camshaft position sensor, and even trying both aftermarket and OEM parts, the no-start condition persisted.
Further complicating the diagnosis, the owner preemptively replaced a significant number of components in an attempt to resolve the issue. These replacements included:
- Fuel pump and fuel pump ECU
- Fuel filter
- Spark plugs and coil packs
- Camshaft position sensor (multiple times)
- Crankshaft position sensor
- Mass airflow sensor
- Timing belt (recently replaced)
Despite these extensive replacements, the 1999 Toyota Land Cruiser remained unable to start. Adding to the mystery, the check engine light would stay on, yet a basic OBD-II scanner failed to retrieve any fault codes. A flickering battery light during cranking further suggested potential electrical issues.
Given these symptoms and the troubleshooting steps already taken, let’s explore potential causes and diagnostic approaches for a 1999 Toyota Land Cruiser that cranks but won’t start. It’s crucial to systematically investigate the key systems required for engine ignition: fuel, spark, and air, as well as the engine’s computer and sensor inputs.
Possible Causes and Diagnostic Steps:
-
Fuel Delivery Issues: Although a new fuel pump and filter were installed, fuel delivery problems can still occur.
- Fuel Pressure Test: The most critical step is to verify fuel pressure at the fuel rail. A fuel pressure gauge is required for this test. Low or no fuel pressure would indicate a problem with the fuel pump, fuel pressure regulator, fuel lines, or potentially a clogged fuel filter (despite being recently replaced).
- Fuel Pump Relay and Circuit: Check the fuel pump relay and its associated circuit. A faulty relay or wiring issue could prevent the fuel pump from operating consistently.
- Fuel Injector Malfunction: While less likely to cause a complete no-start condition across all injectors simultaneously, it’s worth considering if other fuel delivery issues are ruled out.
-
Ignition System Problems: Spark is essential for combustion. New spark plugs and coil packs have been installed, but issues can still arise.
- Spark Test: Perform a spark test on each cylinder. This involves removing a spark plug, grounding it, and checking for a strong spark while cranking the engine. No spark or weak spark indicates an ignition system fault.
- Crankshaft Position Sensor and Camshaft Position Sensor (Signal Integrity): While these sensors have been replaced, ensure the wiring and connectors to these sensors are intact and free from damage. The ECU relies on these signals for timing spark and fuel injection. A wiring fault could negate the new sensor’s functionality.
- Ignition Coil Power and Ground: Verify that the ignition coils are receiving proper power and ground.
-
Electrical System and Immobilizer: The flickering battery light and no-start condition could point to electrical system weaknesses.
- Battery and Charging System: Even with a charged battery, check battery voltage during cranking. Excessive voltage drop can indicate a weak battery, poor connections, or a high current draw elsewhere. Inspect battery terminals and cables for corrosion and tightness.
- Immobilizer System: The 1999 Toyota Land Cruiser may have an immobilizer system that prevents starting if it doesn’t recognize the key. While less common for sudden failures, it’s worth investigating if other possibilities are exhausted. Check for any immobilizer system warning lights on the dashboard during startup attempts.
- Main Engine Relay and EFI Relay: These relays power the engine management system. A faulty relay can cut power to essential engine components.
-
Air Intake and Engine Mechanical Issues: While less probable given the sudden onset, these are still possibilities to consider.
- Airflow Obstruction: Check for any blockage in the air intake system.
- Timing Belt/Chain Issue: Although the timing belt was recently replaced, incorrect installation or belt jump (less likely with a new belt) could cause timing issues leading to a no-start. However, this is less likely given the engine cranks normally.
- Compression Test: In more extreme cases, a compression test can reveal significant engine mechanical problems, but this is usually considered after ruling out fuel, spark, and basic electrical issues.
Conclusion:
Diagnosing a cranks-no-start condition in a 1999 Toyota Land Cruiser requires a systematic approach. Starting with basic checks of fuel and spark, and then progressing to electrical and more complex systems is crucial. Given the troubleshooting steps already undertaken by the owner, focusing on verifying fuel pressure, spark presence and strength, and thoroughly inspecting the electrical system—especially relay and sensor wiring—would be the next logical steps. If these checks do not reveal the issue, consulting a professional mechanic with experience in 1999 Toyota Land Cruiser diagnostics is highly recommended to avoid further unnecessary parts replacements and to pinpoint the root cause efficiently.
