BloatedCow

I have just put about 3000 miles on after a cam + head swap (TSP233/239 5.3l 2.5 stage heads) and it just started to hesitate above 4000K in 3rd and 4th gear while the engine is under load. It feels like there is no power for brief moments while the RPMS rise, almost like it is missing but with no backfire. I had the car tuned at a local shop after which I noticed black deposits building on the bumper above the tail pipes, also the spark plugs had some black carbon like deposits on them the last time I pulled them. I thought this was because of a richer A/F tune, but is this normal? Any ideas where to start trouble shooting would be greatly appreciated.

PREDATOR-Z

compression and leakdown test.

BloatedCow

I checked the cylinder compression the last time I pulled the plugs and all where well above specs in the service manual (180-190 if I remember correctly), I have not performed a leak down test however.

PREDATOR-Z

You should use a software to datalog, could be a sensor, dirty fuel filter, glitch in tune, O2 sensor (I would check those since you're running rich)

BloatedCow

thanks for the suggestion I will look in to some data logging software and check the o2 sensors thanks.