What is the firing order of 1998 6-cylinder Cherokee?

4.0 Liter I6 firing order is 1-5-3-6-2-4 3.7 & 3.9 Liter V6 is 1-6-5-4-3-2 For the 2.8L engine the firing order is (believe it or not) 1-2-3-4-5-6 For the 4.0L engine the firing order is 1-5-3-6-2-4 Often the firing order is stamped on the manifold or posted on a plate in the engine compartment. See section 2, pages 10-11 of Chilton's Guide #40602 for more details.