After putting in the new cam wires etc, car was running pretty well, with some kr.

Got a tune, and put it it, car seemed to run better but still some KR. Put in LT4 KM, adjusted the rockers, and now car is running bad.

The first 10 minutes the car is running, it runs well, no miss. Temp is up around 175 or so. Then the car gradually begins to miss, and it gets worse and worse.


This miss feels like a spark problem, but it would seem to me that it would be present all of the time, not just when the car gets really heated up.

Could an injector leak or fuel filter be the problem? Why would this get worse with temp?


Did a datamaster log after the tune but before the miss showed up, and it looks like my injector DC is around 80-90. O2 mv's are 900-920.

Did a log with the miss. Did one very brief WOT only up to 3600 rpm. DC was only 45 percent but maybe I didn't stay on it long enough.

Any ideas?

 

If it only does it in closed loop then it has to be a sensor.

Try putting your LT1 KM back in it and see if it still does it.

Also, what about your o2 sensors. I've heard of them causing a miss like that.