Toyota 4.6L (281 cu in) firing order — diagram & guide

Back in 2006, Toyota first released the 1UR V8 engine which turned out to be so reliable that it’s still in production for some models today. The brand ended up adding two more engines with the same block design and configuration and slight bore stroke adjustments in the years to come.

However, even though all this goes in favor of the engine being more than solid, you’ll need a Toyota 4.6L (281 cu in) firing order to keep it that way. Don’t worry though, our team has got you covered since we’ll lay down all the important pieces of information in this guide.

Toyota 4.6L 1UR firing order

The Toyota 4.6L 1UR firing order is 1-8-7-3-6-5-4-2, which is not the usual firing pattern for a V8 or a small block V8 for that matter. Toyota used a particular engine block and cylinder head design for the “UR” family of engines, which is also one of the reasons why the firing order is so specific.

That’s why most drivers are confused by the design and the firing sequence of this engine and we wanted to clear that up with our guide. Of course, getting to know the firing sequence won’t get you far when maintaining your car.

You have to apply it properly and that includes identifying each engine cylinder and figuring out the cylinder positions so you can check them according to the firing pattern.

Toyota 4.6L cylinder diagram

The next thing you’ll need to know after the firing order of this engine is how it’s configured. In other words, it’s important to know about all the cylinder positions. In that light, it’s a good thing that the engine is pretty similar to other engines of the same group, including the 5.0-liter one and the 5.7-liter one.

So, you’ll find cylinders 1, 3, 5, and 7 on the driver’s side, and cylinders 2, 4, 6, and 8 on the passenger’ side. The first cylinder is located on the driver’s side or in other words on the left side looking at it from outside the car while standing in front of the engine.

Toyota 4.6L vehicle applications

Among all the V8 engines made by Toyota over the years, the 4.6-liter one is arguably one of the most reliable options. It’s therefore no wonder it has been used in a variety of vehicle models so far, including some Lexus models as well as a part of the hybrid powetrain system.

We’ll list all the options so you can check if your vehicle fits among the ones that use this engine and its specific firing order:

• Toyota Tundra
• Toyota Land Cruiser
• Toyota Sequoia
• Lexus LS460
• Lexus LS460h
• Lexus GX460

It’s common for Lexus models to also include an electric component of the hybrid powertrain along with this engine, but it’s important to note that this doesn’t affect the firing order.

Our take

Overall, the 4.6-liter V8 engine is one of the most durable production V8s that Toyota has made in the last couple of decades. With that in mind, we wanted to give you the one piece of advice needed to make it bulletproof, so we hope that this guide will give you all the necessary steps on that path.