Cant seem to figure this one out. 2007 Impala 3.5, 380000km but well maintained. Runs great for about ten minutes or until you give it a lot of throttle. Then the tach stops working completely. Getting engine misfire code and crank sensor code. Checked all wiring leading to crank sensor and found broken wires and repaired them. Tried new crank sensor, nothing. New plugs and wires also.
Thanks
Tyler

 

On my 2001 Impala, I had a problem where I would loose 1 or 2 coils as the engine got hotter. This would be about 10-15 minutes of driving in January, so it would start and run fine while cold. I initially was going to replace the coil packs as I just thought they were going bad. At the last minute, I swapped one of the coils that had no output with the coil that was consistently running ok. The coil that was working, now did not work and the coil that was not working was working fine. The ignition module that the coils plug into went bad and was temperature sensitive. A new module got it running right with no temp sensitivity. It could be possible your module shuts down entirely.