[BLUE65FB]

I'm having an issue with my truck. While data logging with SCT livelink I turned on the misfire counter and I noticed it has a pesky misfire on cylinder 8. The counter level shows a 1 to a 3 depending on how it's feeling. The truck runs absolutely fine. I've installed new plugs, new coils, new injectors and I also swapped all of the plugs and injectors and coils around. The "misfire" doesn't chase it. Occasionally cylinder 5 shows a misfire count of 1 as well. But mostly just 8.

The last time I drove it while data logging, the misfire counter showed a 1 on cylinder 8 all the way to the gas station. When I turned the truck back on the misfire on cylinder 8 went away and then it showed it on cylinder 5. When I turned into my subdivision, the misfire count went to 3 on cylinder 8. I was idling the entire way..... We even added an extra ground from the battery to the engine.....nothing changes.....

IS THIS REAL?? :yikes:scared003

 

[singlemalt]

A count of 1 or 3? You do not have a problem. If the count is in the thousands then the PCM throws a code I believe. Sounds like everything is running really well on your truck.

 

[BLUE65FB]

That's what I've been thinking but before the new coils I've seen the counter get as high as a 9. I'm running tr6 gapped at 32. My concern is why would the other cylinders show 0 misfire but 5 and 8 show a small pesky misfire?

 

[Painless Autoworks]

What happens at wot? A misfire here and there really isn't much to worry about. I have a truck (chevy 6.0) at my shop now that has 35k misfires on cyl #1 & 65k misfires on cylinder #6.

Not familiar with the SCT misfire software. Maybe try a high end scan tool to read the misfires and verify your concerns? Too bad you are not close, I would check it out.

 

[BLUE65FB]

WOT doesn't affect it, the counter will show a miss of 3 at 10 mph all the way up to 112mph.

 

[Jrock909]

Blue my truck does the same thing with SCT, I often wondered how reliable the misfire counter is....

 

[D3VST8R96GT]

I have never had a misfire counter even when I had an audible misfire lol

 

[01wsvt]

WOT doesn't affect it, the counter will show a miss of 3 at 10 mph all the way up to 112mph.

That truck will run 112mph??? LOLotstirring

 

[BLUE65FB]

Haha I'm sure you know how it is. There was a strong wind that day!!!:hifu:laughing25

 

[Modular Big Bore Stroker]

You have to understand what constitutes a mis fire to the pcm. From the time it fires or pulses the coil it's looking for a set amount of crank degree's of rotation, if the minimum is not met it logs a misfire. It has a set way of storing this info and certain criteria has to be met to invoke a CEL.

In it's an imperfect system and is programmed to ignore misfires when certain criteria is met.