Car went in for Head Gasket replacement. After the job, mechanics started the car 4 times.....now it won't start at all. We get fuel but no spark. With computer connected you can disconnect the crank sensor and no codes are thrown. Computer says everything is normal.

 

Check that the cam is still in time. Timing belt could have jumped if not tensioned properly.

Are the spark plugs firing? Take one of the coils out and put a spare plug in it, reconnect the wires then hold that plug against the engine and crank.

 

Spark plugs are not firing. You can smell gas so I assume it is flowing.

 

Not throwing any codes