I originally posted this on the Powertrain, but realized that the Engine would be a better place for it, so my apologies for the double post.

Hi, all! I'm having a cylinder that is missing steadily, even at idle. My code reader says it's #6 so I replaced the COP with a new one, but the problem is still there. Then it occurred to me that perhaps the cylinder numbers might not be conventional on the Triton engine. Most engines I've worked on the #1 is at the front driver side, #2 front passenger, then back and forth all the way to the back. Meaning 2, 4, 6, 8 would be on the passenger side. Is this correct? If so, and with a new COP in place, this only leaves the spark plug, right? Or am I maybe missing something.
Any advice would be appreciated.
Thanks,
Deke

 

Firewall

4 8
3 7
2 6
1 5

front

 

Thanks much for the response, but now I'm more confused than before. I'd previously had a bad COP that was #8 and I replaced it which fixed the problem. That was a couple years ago. #8 was at the firewall, passenger side. Am I misinterpreting something?
5.4, 1999 F150
Deke

 

Yea, I believe you may have confused the ford cylinder order with the chebby.

The layout previously given to you is the correct one.

 

Thanks folks. I guess I need to go back to the drawing board. Since I made the mistake of assuming all manufacturers numbered their cylinders the same I've obviously replaced the wrong COP. No wonder it didn't fix the problem. I'm surprised that after more than a hundred years they haven't standardized cylinder order. Such is life... Now, back to work.
Deke

 

- Sucks donut - That was a couple of years ago?? - Should be like a new truck now..

 

Back again to say thanks to those above who offered help in giving me the correct cylinder order. Now that I've replaced the COP on the "correct" cylinder, the engine runs like it's supposed to again. That's the second one I've replaced in two years and the truck only has 78k on it. Fortunately they're cheap.
Great site.
Again, thanks.
Deke Morisse
99 F150 Lariat 4x4 Ext Cab

 

Just keep hanging out here, you'll catch on