Misfire diagnostics are often "disabled" when tuning for a cam. By disabled, I mean that the thresholds for the DTC's are raised so high that the PCM will never set a P0305 to lead you to cylinder #5.(or other cylinders)

You'll need to change the tune if you want to use the PCM misfire diagnostics.

 

Yea right now the misfire tables are maxed. I will set them back to stock and drive the truck during the week to see if I can narrow a cylinder down. The problem is that it only misses real bad after 90 miles or so.

If it was a true misfire, would I be able to see it on the wideband?

 

Not always.

 

Thanks, I will build a misfire config

 

How are you feeding that 408??? What Pump, Injectors, what Fuel Pressure??? Do you have a fuel pressure Gauge hooked into the fuel system???

 

The only thing I've done to the fuel system is add a vacuum referenced fpr. I don't have a gauge inside the cab to see fuel pressure, only in the engine bay. Base pressue is set to 58psi with LS3 42lb injectors.

 

Stock fuel pump?? For realz??

 

Hell yea. haha AFR is solid at 0.87 lambda down the 1/4 mile.

 

X2... I beat it's killing that Biotch trying to keep up.

 

Yea I bet it is too. I watch the wideband like a psycho but it still hasn't given up.