Parts for your 2004 Toyota Land cruiser-Ignition coils

2004 Toyota Land Cruiser ignition coils — what they do and when to replace

Per Toyota’s factory repair information for the 2004 UZJ100 with the 4.7‑litre 2UZ‑FE petrol V8, this Land Cruiser runs a direct‑ignition, coil‑on‑plug system with eight individual ignition coils (one per cylinder). Toyota’s electronic parts catalogue backs that up by listing a coil assembly per cylinder on petrol models. Diesel variants (1HD‑FTE, 1HZ) don’t use ignition coils at all because they rely on compression ignition rather than spark, so the part isn’t fitted on those engines.

On petrol 2004 Land Cruisers, the ignition coil’s job is to step up the 12‑volt battery supply to the high voltage needed to fire each spark plug. Because the system is coil‑on‑plug, there are no traditional high‑tension leads, which helps with reliable spark delivery and cleaner emissions. When coils get tired, they can cause misfires, sluggish performance and poorer fuel economy.

Typical signs a coil may be on the way out include:

• Rough idle, hesitation under load, or a flat spot.
• Check engine light with misfire codes (often P0301–P0308).
• Hard starting and higher fuel use.

There’s no fixed replacement interval for coils on the 2UZ‑FE, they’re replaced when faulty. A smart time to inspect them is during spark plug servicing (iridium plugs on many 2UZ‑FE applications are typically due around the long‑interval mark). With coils off for plug changes, check each coil boot for cracking or carbon tracking, and apply a small amount of dielectric grease to the inside of the boot before refitting.

For ongoing reliability, keep moisture and oil out of the plug tubes, ensure the engine cover and wiring clips are secured, and avoid yanking on connectors. If one coil fails at high kilometres, many owners replace just the faulty unit and keep a spare in the glovebox, others prefer a full set to minimise future downtime. Either way, use quality coils that meet OE spec.

DIYers should disconnect the battery, remove the engine cover, unplug the coil connector, and undo the small coil retaining bolt. Refit in the reverse order and tighten to the factory specification shown in the Toyota repair manual. If misfires persist after replacing a suspect coil, check the spark plug on that cylinder and confirm there are no intake or vacuum leaks.

Popular questions about 2004 Toyota Land Cruiser ignition coils

How many ignition coils does a 2004 Land Cruiser have?
The 4.7‑litre petrol V8 has eight individual coil‑on‑plug ignition coils, one per cylinder. Diesel models (1HD‑FTE, 1HZ) don’t use ignition coils at all, as they ignite fuel by compression rather than spark.

Do ignition coils need routine replacement?
Coils aren’t a scheduled service item. Many last well beyond 150,000–250,000 km. They’re replaced when symptoms or diagnostics point to a misfiring cylinder. Inspect coils whenever spark plugs are changed, and replace any with heat‑cracked boots or signs of arcing.

Is it okay to keep driving with a misfiring coil?
Best not. While the vehicle may still run, driving with a misfire can overheat and damage the catalytic converter and increase fuel use. It’s wise to diagnose the fault promptly and replace the offending coil and/or spark plug to protect the engine and exhaust.