After replacing head gasket, engine cranks normally, but no spark from coil pack. What could be the problem. And how can I test the crank and cam sensor. Then can I test the crank sensor and cam sensor if they are found to be the problem?
There are specific special test instruments to check sensors, I would do a code clear, this will remove all codes in the system, then attempt a re start, then do a scan and see what new codes are set, do not presume anything as you will end up spending money on things that are ok. Re post any fresh codes set.