I have 1998 epxpedition my engine light is on truck run rough ,I t is saying the number cyl is miss firing I need to know what is the firing order on the expo it is a 5,4l. I think it may be the ignition coil

An auto parts store does not give out advise

They are parts counter sales people-- not mechanics

Spark plugs seldom fail in your lifetime, so you need to
check for vacuum leaks at O2 Sensors,Exhaust leaks,Vacuum leaks
in inlet ducting ,pcv vacuum leaks,egr system issues

Check & listen to hear if injector all click & have same resistance

An OBD Codes for a cylinder doesn't have to be correct

You have mechanical integrity also

You don't have the tools to test as needed I don't suspect
or you could check cyl contribution,fuel trim,fuel press,cyl misfire
counts,O2 switching times,etc

Hei, the most likely is a fault ignition cassette or injector nr 5!? If you have a scope and know how to use it, is easy to see where is the fault!

The number 3 plug is the third one back from the front of the engine. They are numbered in order 1,2,3,4,5,6 front to back, this is the cylinder numbers not the firing order. Firing order is 1-5-3-6-2-4 .

You didn't state what year or engine size, this image is for 1980 to 1996 nissan, but it should help.



4 cyl. firing order is 1-3-4-2
V6 firing order is 1-2-3-4-5-6

V8 engines as follows:

289,302,5.0L(Carb.)
390,406,427,428
400,460

(cyl numbers)

Front (engine)
5 1
6 2
7 3
8 4
(firing order)
1-5-4-2-6-3-7-8


5.0L EFI
351, 5.4L, 5.8L

(cyl numbers)

Front (engine)
5 1
6 2
7 3
8 4
(firing order)
1-3-7-2-6-5-4-8

Hope this helps, let me know.

You didn't post your engine size so please pick the applicable diagram:



1996-98 4.3L Engines Firing Order: 1-6-5-4-3-2Distributor Rotation: Clockwise



1996-98 5.0L, 5.7L and 7.4L Engines Firing Order: 1-8-4-3-6-5-7-2Distributor Rotation: Clockwise




4.3L Engines Firing order: 1-6-5-4-3-2 Distributor rotation: Clockwise



4.8L, 5.3L and 6.0L Engines Firing order: 1-8-7-2-6-5-4-3 Distributorless ignition system (one coil on each cylinder)



5.0L, 5.7L and 7.4L Engines Firing order: 1-8-4-3-6-5-7-2 Distributor rotation: Clockwise

Cylinders are numbered from front to rear (grille to firewall) passenger side: 1-2-3, driver's side: 4-5-6. Firing order is 1-4-2-5-3-6
Did you check by pulling #2 out while the engine is in idle to see no weakness from the engine? BTW your coil pack cost $80.

You have a cylinder misfire. You need to check the distributor, wires, and pull the plugs because something is not firing the fuel mixture in one or more of your cylinders at timew. you can do the plugs yourself for the most part. I dont know how the 6 cyl looks in the engine compartment of the wrangler, but from my experience with a 96 XJ, number 6 cylinder is very difficult to get to because of the interior air intake vents. if all the plugs seem fine, you may want to take it into a shop for a distrubutor and wire check

cannot be specific, had a 98 (now a 99). remember they fire twice- compression and exhaust. if you don't get and answer soon, look up firing order and everyother one should fire together, limiting combinations to two. It doesn't care what stroke it is on

Cracked spark plug, damaged worn plug cable, the clicking, thumping is a result of operator forcing engine to run out of synch, as result of electrical combustion loss. the fact the vehicle continues to run rules out any problem with fuel line - fuel components. Let us know the outcome please.