The Jeep 4.0 inline-six is an iconic engine and one of the most popular motors ever produced.
It was discontinued in 2006 but is still wildly used by many Jeep owners and continues to be a great motor with many enthusiasts.
It was originally developed and built in the 1980s, expanding upon the long history of knowledge and experience the brand had over the years.
Introduced by AMC in 1986 the engine was the main power plant for Jeep from 1986 to 2006, making it one of the more popular engines and widely available in secondary markets along with parts.
The Jeep 4.0 has an excellent crankshaft balance with seven main bearings. This keeps balancing well with fewer vibrations.
With a very good build quality, Jeep is known for the 4.0 inline-six engine will continue to be a very popular engine with owners for many more years.
What is a Jeep 4.0 Firing Order?
1-5-3-6-2-4
A Jeep 4.0 firing order is 1-5-3-6-2-4. The number-1 cylinder is at the front closest to the radiator.
The number-6 cylinder is the farthest to the back closets to the firewall.
Which Direction Does the Rotor Turn On a Jeep 4.0?
Clockwise
The rotor turns clockwise inside the distributor cap.
Matching the number-1 cylinder with the correct spark plug wire is often done by removing the number-1 spark plug and feeling if the piston is at the top.
The piston will be at the top of the cycle twice, one of which is for the spark plug to send a spark and ignite the gas.
Once the number-1 cylinder is known on the distributor, the firing order can be followed to match it correctly.